Retracing the steps of Mark Dennis, 'brilliant' barrister with a dark side

Warning: This article contains references to child sexual abuse and suicide.

There is a small terrace house in Sydney's inner west that always gave builder Chad Loxsom an uneasy feeling.

"I've been in thousands and thousands of people's houses," he said, but this one "was a little bit strange".

The Leichhardt property belonged to Mark Dennis SC, a criminal defence barrister, who Loxsom said had a "weird demeanour" and was "just odd".

But what he saw inside is what gnawed at him for years.

"All over the walls of his house, he had dozens upon dozens upon dozens of pictures of him with little kids," he said.

In some photos, Loxsom said Dennis was hugging shirtless children.

Loxsom shared his suspicions with an electrician.

"His gut was this guy was doing something bad with kids as well," he said.

The electrician first noticed the "come back with a warrant" doormat, and then the large mirror fixed to the ceiling above Dennis's bed.

But, like Loxsom, what really alarmed him was the sheer volume of photographs in almost every room, even the kitchen.

"It was just disturbing. Like, these kids weren't happy," he said.

Eventually, Loxsom decided to make a report with the child protection hotline.

"I didn't do it straight away, which now I regret," he said.

In January, Dennis came onto the police's radar again when he was searched at Sydney Airport as he returned from a trip to Cambodia.

What was found on his devices led to his arrest, a raid of his house, and child abuse material charges from evidence prosecutors described as "disturbing".

Dennis was released on bail, and soon after, was found dead in his home.

Last week, Background Briefing and ABC Investigations revealed his death did not bring the police investigation to an end.

Codenamed Operation Queenstown, Cambodian and Australian national police have been quietly probing Dennis's network and links to famous children's charity Sunrise Cambodia all year.

The ABC travelled to Cambodia in June to retrace Dennis's steps to reveal the inside story of how an accused predator accumulated power within a high-profile charity and gained access to vulnerable children.

In an investigation that combines a tranche of internal documents with dozens of interviews, the ABC can reveal allegations that Dennis sexually harassed a former Sunrise staff member and made teenage girls feel uncomfortable by excessive touching.

The claims raise important questions for all children's charities that must balance the need to fundraise with child safety, as multiple former Sunrise staff say they saw Dennis's bad behaviour but felt they could not report it.

"They saw this," one former staff member told the ABC through a translator. "But they could not do anything because he's a big sponsor."

A spokesperson for Sunrise said they were never aware of any complaints about Dennis and police had told them no current or former Sunrise child had been identified as one of his victims.

The charity defended its child protection policies, saying the children always came first.

'Married to the profession'

Dennis grew up in a large family on Sydney's northern beaches, and by 2001, was a criminal defence barrister with a room at the prestigious Forbes Chambers.

"You don't get to go to Forbes unless you are absolutely brilliant," says one solicitor who briefed Dennis.

"He was one of those people who was married to the profession."

His nickname was "Dark Menace" — a play on words that several acquaintances said reflected his personality and black sense of humour, exemplified by his "WASNTME" personalised number plate.

Across his career, Dennis was known to have mentored junior lawyers and published papers under provocative titles and on topics like defending accused paedophiles and cross-examining child witnesses.

"You need to watch the child witness carefully and assess matters such as intelligence, level of vocabulary and articulation, degree of self-confidence, general demeanour," he wrote in 2017.

One lawyer who knew Dennis for more than a decade said he was "not shocked" by the charges because he had a reputation for sexual harassment and aggression towards women.

"It's one of those situations where, and I know I'm not the only person who's thought about this, I think a lot of us in retrospect are like, 'This was actually f***ing obvious,'" he said.

Three lawyers told the ABC about an incident where Dennis was intoxicated at the 2012 Aboriginal Legal Service (ALS) Christmas party in Sydney, when he lunged at a woman with an open fist.

He was then banned from ALS Christmas parties.

Barrister Charles Waterstreet, who worked at Forbes alongside Dennis for more than a decade until facing his own sexual misconduct allegations, described his former colleague as "very ambitious" but "an oddball".

"He loved a drink, especially on Friday nights," he said. "He sort of became another personality."

In 2011, Dennis began hosting legal conferences to raise funds for his charity, Reasonable Cause, that pledged to help "disadvantaged young Cambodians to further their education".

Tickets cost $450, and the guest list included magistrates, silks and politicians, according to the 2024 invitation.

In interviews with more than 20 sitting Forbes barristers, some were quick to defend their late colleague — insinuating the evidence was thin, based on industry rumours, and one said they did not think his charity work should be "smeared".

"It did such good work. I don't think it was connected … to some sexual interest," they said.

However, despite some celebrating his work and attending his legal conferences, many could not name the charity the money went to.

From sponsor to chairman

The largest recipient of Dennis's fundraising was Sunrise Cambodia — a high-profile children's charity founded by Adelaide-born Geraldine Cox.

Cox has spent decades crisscrossing the globe, and according to her 2011 report, delivering speeches to company executives in the United Arab Emirates, government officials in Australia, private schools, and lawyers like Dennis.

"I flew to Sydney to address a group of lawyers at an event arranged by sponsor Mark Dennis, where over $14,000 was raised. Who said lawyers do not have hearts!" Cox wrote.

Her work has been celebrated internationally. She has won awards, been praised by Australian media and rubbed shoulders with Hollywood celebrities and Australian prime ministers.

Starting in 2008, Dennis personally sponsored a handful of children at Sunrise whom he visited in the orphanages each year. Over time, he backed the whole organisation — raising at least $340,000 in seven years through the legal conferences.

In 2010, he also began funding and attending Sunrise's annual beach holidays to Sihanoukville, a once-sleepy Cambodian coastal town now filled with scam compounds and casinos.

Itineraries for these trips obtained by the ABC show the children played football, shared meals, performed concerts and socialised with sponsors, including Dennis.

Photographs from these trips show Dennis on the beach, and hugging and playing with young children at the hotel. There is no suggestion the photographs are sexual.

A spokesperson for Sunrise said sponsors were not permitted to initiate contact with children.

"However, if a child comes running at a sponsor for a hug, the sponsor is not expected to push them away as this can be very emotionally damaging to a kid who may actually feel safe for the first time in his/her life," they said.

A former Sunrise employee told the ABC it was during one of these beach trips that Dennis was swimming when he went under the water and touched her leg in a sexual manner.

"I felt really afraid," she said. "I kicked Mark off. I was very terrified. He apologised later."

A Sunrise spokesperson said the charity did not know about this allegation and was "very sorry to hear this".

"Had they reported this, we could and would have dealt with it at the time," the spokesperson said.

The woman did not complain formally, but said staff were concerned about Dennis's behaviour and agreed they needed to be "careful" around him to "protect the kids".

The same former employee said she was also concerned about Dennis's behaviour towards an autistic teenage girl living in Sunrise, whom he regularly tried to come close to, and touched her breasts.

She said she saw Dennis entering the girls' and boys' bedrooms at Sunrise, but staff felt there was nothing they could do "because he's a big sponsor" and therefore did not report this.

Eng Sopheak, who lived at Sunrise from the age of five and then worked as Cox's personal driver, also said he witnessed Dennis regularly entering the girls' dormitories.

"I was personally worried," he said, because men were typically not allowed to enter the dormitories.

Sopheak said there needed to be greater separation between sponsors and children.

"My recommendation to sponsors is just that they donate the money, but they don't need to have a relationship with the child," he said.

"So I'd want it to stop."

A spokesperson for Sunrise said dormitories were private areas and as of last year, sponsors were no longer invited to Sihanoukville. They said they had plans to phase out individual child sponsorship but did not specify when.

However, Sunrise's website still allows sponsors to preference the age and gender of children whom they can visit for $50 per month.

'Big boss'

By 2018, Dennis was appointed chairman of the Australian Cambodian Foundation, the registered Australian charity managing donations for Sunrise at the time.

In this role, Dennis was involved in almost every aspect of Sunrise's operations — managing redundancies, approving wages, signing off on hiring policies and even becoming a 49 per cent shareholder of Sunrise's Sihanoukville property, which was valued at more than $US3 million in 2017.

"He was the big boss," said Yi Soksan, who held senior positions at Sunrise between 2011 and 2018.

Soksan said staff were told by Cox to "just trust" Dennis because he was a donor and lawyer, and recalls her saying: "He's my friend, he's one of the big donors and sponsors. He loves Sunrise."

"She advised us, 'He's also the lawyer, so he understands, you know, the rules, the laws. So, just trust him.'"

Cox said she had no recollection of discussing Dennis with staff. While she considered him a friend, she said she had no knowledge of his personal life and never witnessed any bad behaviour.

While chairman, Dennis wielded power over Cox. In an email sent in November 2019, Cox asked for his approval for Sunrise to cover personal expenses.

"Since I offered to reduce my salary … around the time you took over, Mark, I am finding it increasingly difficult to have any sort of normal life," she wrote.

He agreed.

While their relationship was financial and social, it was also fractious.

Emails show Dennis privately described Cox as an "unreliable historian" and "something of a compulsive spender" — descriptions Cox said she could not comment on.

Dennis was granted access to Sunrise's bank accounts in 2018, allowing him to use Sunrise's money to make purchases for children.

Sunrise said this was normal practice, and its current policy permitted donors to purchase gifts for individual children on special occasions like birthdays, capped at $20 per year.

Maggie Eno, who runs Cambodian child welfare charity M'Lop Tapang, was critical of everything from sponsors attending beach holidays to giving gifts to children.

"Individual purchasing … it's grooming," Eno says. "It's horrifying."

Eno, who did not want to comment on Sunrise specifically, said sponsors should never have access to children because criminals were "sophisticated" and "always" had the goal of getting "direct access to the children".

"Paedophiles or child sex offenders don't just groom the child, they groom the family of the child, and they groom the organisation taking care of the child," she said.

"The majority of people are good, kind people, but there is always a risk."

A spokesperson for Sunrise said work was underway to distance relationships between sponsors and children.

'Godfather'

Former Sunrise resident Sok San, now aged 28, was among the children Dennis bought gifts for and socialised with on the beach trips.

He first learned that Dennis was charged and had died when contacted by the ABC, and said he cried.

"He promised to buy me an iPad," San said in June, adding Dennis wanted him to download Facebook on the device.

San said his mother died when he was young, there was violence in his childhood, and he started living in Sunrise at around 10 years old.

He first met Dennis in the orphanage as a child and said Dennis bought him a small watch and gave "toys, books and cookies" to other children.

"He's a good person, and he also came to watch a traditional dance," San said.

He called Dennis "godfather" and said they kept in touch outside Sunrise when he became an adult. They met for ice cream in Siem Reap, and Dennis made promises, like paying for his university studies in America, he said.

Dennis also continued relationships with other children outside Sunrise after his chairmanship ended in 2020.

Facebook messages obtained by the ABC show Dennis maintained direct contact online with children he met through Sunrise.

"I am incredibly proud of you," Dennis wrote to one boy in September 2024.

"Thank you for your support all the years," the boy responded.

Behind Sunrise's gates, emails show staff had been concerned about these relationships for years.

One email shows an employee contacted Sunrise's former operations manager, Rob Madsen, in 2020 for help when he learned Dennis was sending money to a 17-year-old outside Sunrise.

"He has been still supported by Mak [sic] Dennis," the email said. "Many kids living outside [Sunrise] have been supported/sponsored by him secretly."

"Kids requested me to keep it secret as he doesn't want [Sunrise's] managers to know about his support. He buys motorbikes for all kids, school fees, etc."

Sunrise said it had no record of this. They said all children were trained on the dangers of maintaining contact with sponsors after leaving the orphanage, but Sunrise did not have the power or resources to monitor what graduates did.

Final visit

Dennis flew to Cambodia for one final trip in January this year, where he visited Cox's personal residence, a wooden villa on the grounds of Sunrise.

He was in Cambodia on a golfing trip, Cox said, and saw her as a "concerned friend" after hearing she was bedridden following a fall.

Little did she know, this would be Dennis's last visit to Sunrise.

When he returned to Sydney, he was intercepted by Australian Border Force officers at the airport who searched his devices and allegedly discovered child abuse material.

Documents released to the ABC under Freedom of Information laws reveal Dennis was communicating this material between 2023 and 2025 to two people, including an account with an Australian number and username "Kanje".

Dennis denied possessing child abuse material in a police interview, but never entered a formal plea.

In a bail hearing the following day, prosecutors said they had discovered an image of a boy aged between six and 10 on his phone, and chat logs where he expressed a desire to rape a 16-year-old.

Commonwealth prosecutor Jon Kisch described the material on Dennis's phone as "disturbing" and "very serious offending", which, if proven, would attract a long jail sentence.

The judge allowed Dennis to be released under strict conditions. Less than three weeks later, he was found dead, leaving behind many unanswered questions.  

"I want to know what happened," said one young woman Dennis met through Sunrise.

“I want to know [if] this is true or not. I want to know why. I want to know what happened to him.” 

Listen to Dark Menace, a new three-part investigative podcast from Background Briefing and ABC Investigations, via the ABC Listen app or wherever you get your podcasts. Follow Background Briefing podcast to be notified when future episodes drop.