The son of slain north Queensland woman Dorothy Britton has been charged with her murder, 22 years after she was slain with a shotgun blast to the head.

Christopher Mark Britton was arrested by Queensland detectives on Thursday in Brisbane after recent leads had led to him being questioned in his home state of South Australia.

Dorothy Britton shortly before a shotgun blast ended her life. Photo: AAP

The 51-year-old Port Neill resident appeared in the Brisbane Magistrates Court on Friday but made no application for bail.

Defence lawyer Adam Magill said his client was shocked to have been charged with his mother’s alleged murder.

“He’s fairly distressed,” he said outside court.

“He’s strenuously denying the matter. The matter will be challenged.”

Mr Magill said Britton, who was 29 at the time of his mother’s death, had been living in South Australia and doing odd jobs.

“He’s been estranged from his family for the past 17 years so he’s had no communications and something like this has just come out of the blue,” he said.

Ms Britton was last seen on March 6, 1996.

Her body was found the next day after relatives could not reach her and went to check on her.

When they arrived, the front door was open and her protective Rottweiler was standing on the verandah.

There were no signs of a struggle and Ms Britton’s handbag, containing cash, was not touched.

A shotgun missing from the property has never been found.

Ms Britton’s other son, Adrian, last month said suspicion had torn his family apart and he only trusted his younger brother, while “every other person on the planet” was considered a suspect.

Detective Senior Sergeant Chris Knight said police had believed the mother-of-three knew her alleged killer.

“It was a tragic, violent end to her life … a lady that is in her own house minding her own business,” he said on Thursday.

Det Snr Sgt Knight also previously said investigators believed the alleged killer had confessed to others and there were people out there who possessed information about the case.

Britton’s matter will return to court on July 16.

– AAP