Police continue search for potentially armed man in rural Queensland

A potentially armed man remains missing after he disappeared more than six days ago on a rural highway.

Marcus Bismark, 44, was last seen walking along the Gregory Developmental Road in the Greenvale area, about 250 kilometres west of Townsville, on Saturday afternoon after his vehicle broke down.

He is believed to be in possession of a firearm and travelling on foot.

Queensland Police launched a search operation and deployed specialist police to the area earlier this week.

Mr Bismark is described as being approximately 180 centimetres tall with a solid build and dark complexion.

He was last seen wearing long, black pants and no shirt.

His family hold concerns for his welfare due to a medical condition.

Members of the public are being warned not to approach Mr Bismark but to report any sightings to Triple Zero (000).

Police are also appealing to anyone with dash cam footage that may show Mr Bismark in the region to come forward.