A MAN who claimed he had eaten human flesh as a child murdered his former housemate as part of a "sadistic sexual" killing, according to a mental health expert.

A just-published Queensland Mental Court decision gives a unique insight into why Robert Ian Logan stabbed Benjamin Huntingford to death at their home on June 21, 2006.

Logan, now aged 24, was found guilty in the Brisbane Supreme Court in April last year of murdering Huntingford in a frenzied knife attack before stabbing his pet dog "Butch."

The Courier-Mail at the time revealed Logan had told police he had a taste for human flesh and drank Huntingford's blood after killing him.

Huntingford's blood, a jury was told, also had been used to write an obscenity several times and "Where's M money" on walls and a fridge at the house.

The motive for the killing was never made fully clear during the trial, but a Mental Health Court decision by Supreme Court judge Anthe Philippides from March 2010 contains psychiatric material that sheds some light on Logan's motives.

Justice Philippides, in her just-published decision, found that based on psychiatric evidence Logan was fit to stand trial.

One report, from eminent psychiatrist Dr Jill Redden, said Logan's motivation for murdering Huntingford may have had sexual connotations.

"(Logan's) account of the psychotic symptoms is not consistent with most psychotic illnesses," Dr Redden said in her November 2009 report.

"The killing of Ben Huntingford was extremely brutal and involved considerable suffering to the victim. There was clearly a significant sexual aspect to this crime.

"The sexual nature of the crime has never been explained. The factual details of the crime raises the likelihood of a sadistic sexual motivation being a significant aspect of this crime."

Huntingford's father, Peter, last year told a jury Logan was renowned for telling "bizarre stories" and once spoke of travelling to New Zealand as a child and eating human flesh with cannibals.

Logan, who still denies murdering Huntingford, was sentenced to life imprisonment.

Logan told investigators his motivation for the killing was the result of an unwanted homosexual advance made by Mr Huntingford when they lived together.

"(Logan) asserted he drank some of the deceased man's blood," the jury was told.

Originally published as Sadistic, sexual urge drove killer cannibal