A Queensland man accused of the bashing murdering South Korean woman Eunji Ban in Brisbane has been declared unfit to stand trial due to a major psychiatric illnesses.

Alex Reuben McEwan, 21, has been in custody since November 24, 2013, when the badly battered body of Ms Ban was found in Wickham Park in Brisbane's CBD.

The 23-year-old had only been in Australia for six weeks when she was allegedly bashed to death on her way to her job as a cleaner.

McEwan's matter was heard in the Queensland Mental Health Court before Justice David Boddice and two assisting psychiatrists.

Justice Boddice ruled last month he was unfit to stand trial, however the matter was unable to be reported for 28 days after the decision was handed down.

During the hearing the court was told McEwan admitted to his mother that he had murdered a woman and confessed in a police interview following his arrest.

While he was under the influence of alcohol and possibly cannabis at the time of the offence, his mental state deteriorated rapidly after his arrest.

McEwan allegedly told police that he had longstanding feelings he would kill somebody, the court heard.

"He described an ability to communicate with God and the devil," Justice Boddice said.

"He also described the television mirroring what he thought."

A psychiatrist diagnosed him with a number of mental health disorders and he has since undergone electroshock therapy.

Three psychiatrist witnesses concluded McEwan was of sound mind at the time of the offence, but that his current medical condition made him unfit to stand trial.

They rejected the possibility he was feigning mental illness to avoid a trial, but believed his unfitness may be of a temporary nature.

Justice Boddice accepted their evidence that McEwan was temporarily unfit for trial.

"It may well be that in time, the defendant's mental illness will become sufficiently controlled, such that he will be fit for trial," he said.

"It is unclear when that situation may occur."

Justice Boddice ordered that McEwan be subject to a forensic order requiring his continuing detention.

AAP