The man accused of going on a deadly stabbing rampage in central Sydney on Tuesday will defend the charges laid against him on the grounds of mental illness, his lawyer says.

Key points: Sydney stabbing accused Mert Ney appeared before court via video link on Saturday

Sydney stabbing accused Mert Ney appeared before court via video link on Saturday Mr Ney is facing five charges, including murder and attempted murder

Mr Ney is facing five charges, including murder and attempted murder His lawyer says his client will defend the charges

Mert Ney, 20, appeared briefly at Parramatta Bail Court via video link from Surry Hills Police Station where he was charged last night.

His lawyer Zemarai Khatiz told the court his client requires medication for pain relief and mental illness.

Mr Ney was charged with the alleged murder of 24-year-old Michaela Dunn and the attempted murder of a 41-year-old woman.

The other charges include wounding a person with intent to cause grievous bodily harm, intentionally choking with recklessness and common assault.

He allegedly killed Ms Dunn at a Clarence Street unit before stabbing Linda Bo at the nearby Hotel CBD and running around the city streets brandishing a bloody kitchen knife.

He was apprehended by bystanders, who pinned him down using a chair and milk crate, until police arrived.

Mr Khatiz told reporters outside the court that his client would defend the charges.

"He's going through a very difficult situation at this time," Mr Khatiz said.

"But in relation to the allegations he will be defending the charges under grounds of mental illness.

Michaela Dunn, who died on Tuesday, was a keen traveller and had recently visited Sri Lanka and the USA. ( Instagram )

"It will be a matter for trial at a later time."

He did not apply for bail and his case will return to court on Monday.

The magistrate ordered he be seen urgently by Justice Health.

Mr Ney underwent psychiatric treatment and surgery on his leg after being apprehended by bystanders while allegedly wielding a knife in Sydney's centre on Tuesday.

He was treated at Royal Prince Alfred Hospital before being released and taken to Surry Hills Police Station after midday on Friday.