A Brisbane man facing the death penalty after a Sudanese court found him guilty of murder will likely appeal the verdict, his family says.

George Forbes, 45, had been working for a private Kenyan company in southern Sudan when he was arrested in March and charged with murdering Ukrainian flight engineer Mykola Serebrenikov.

Mr Serebrenikov was found hanging from a towel rack in the company's compound in Rumbek, southern Sudan, shortly before Mr Forbes' arrest.

A post-mortem examination concluded the death was suicide but Mr Forbes and two colleagues, both from Kenya, were charged over the death.

Mr Forbes was found guilty and is being held in prison until sentencing.

There is no indication at this stage as to when this may be, but the judge is currently consulting with the victim's family to see if they want the death penalty imposed.

However, Gerald Forbes, a relative of Mr Forbes who is helping coordinate his defence, said they would fight the guilty verdict and were preparing to launch an appeal.

"We are all a bit depressed about the verdict," he told The Age online via email from Africa.

"It now looks like we are in for the long haul on this case."

A Department of Foreign Affairs and Trade (DFAT) spokesman said that every assistance would be afforded to Mr Forbes to ensure his rights are protected during any appeal process.

"The ambassador in Cairo, who is accredited to Sudan, is being sent back to Rumbek to take whatever steps are necessary to ensure Mr Forbes' legal rights, health and welfare are protected," the spokesman said.

A good friend of Mr Forbes, Chris Vautin, said he was "absolutely bloody shocked" by the verdict against his friend of 20 years.

"I guess when you talk to people who are relatives of people who've committed crimes they always tend to say they can't imagine the person being guilty," Mr Vautin told the Brisbane Times.

"But the fact of the matter is I can never imagine George doing what they've claimed he's done."

Mr Vautin said Mr Forbes had been living a nightmare since his arrest, and that he had grave concerns for his friend.

"Apparently the jail is quite disgusting - we're talking about wandering around up to your ankles in human faeces and urine and vomit, and so George got pretty sick in jail," he said.

"What the outcome will be I honestly don't know."

©AAP 2007