The Brisbane man accused of bashing to death Korean student Eunji Ban admitted to police he "bashed the s*** out of her face" while she screamed for help, a Brisbane court hears.

Alex Reuben McEwan admitted to causing Ms Ban's death in 2013 but denies it was murder, saying he felt like he was possessed at the time.

The court heard on Tuesday that Ms Ban had such severe injuries to her face a paramedic was initially unable to determine her gender.

McEwan went into detail about the attack with police during his arrest, with the audio played in the Supreme Court on Tuesday.

Ms Ban's body was found in parklands in Brisbane's CBD on November 24, 2013. ( ABC TV News )

"I bashed the s*** out of her face," he said.

"She just screamed for help.

"I feel sorry for the Asian girl and her family."

Police asked McEwan if he had a mental illness and he said there was a demon in his head.

"A f***ing demon ... it's been troubling me my whole life," he said.

"It's been troubling me since I was born, really.

"On the night of the murder I just woke up randomly and did it.

"I was kind of waiting for it my whole life."

A police officer asked "waiting for what?"

"To kill someone," was McEwan's reply.

The body of Ms Ban, 22, was found badly beaten in Brisbane's Wickham Park in November 2013.

Gender indistinguishable initially

Paramedic Andrew Speakman told the court he was dispatched to the crime scene to check for signs of life but he initially could not tell the victim's gender.

"It was quite obvious it wasn't likely she was alive," he said.

"[There was] gross trauma to her face."

Ms Ban's parents (2nd and 3rd left) outside the Supreme Court in Brisbane on Monday.

The jury was shown forensic photos from the crime scene of large blood stains as well as Ms Ban's body and clothing.

Sergeant Carl Streeting told the court her shirt was "saturated with blood".

'McEwan in jolly mood day before alleged murder'

McEwan's friend Amy Stringer told the court she was drinking with the accused at his unit the night before Ms Ban's death.

"He just seemed jolly I guess, normal, not too out of it," she said.

"He seemed quite casual."

Another friend, Alexander Urquhart testified he had never seen McEwan act violently towards strangers.

"On this particular weekend did you notice anything unusual?" Prosecutor David Meredith asked.

"Nah, nothing unusual," Mr Urquhart replied.

The trial continues.