The 33-year-old Bangladeshi national suspected his wife, Khondkar Fahi Elahi, was having an affair and moved to confront her about it.

It will be alleged Mr Ahmed demanded to look at his wife's mobile phone before he found what he perceived to be messages suggesting an extramarital affair.

An argument ensued, escalating to the allegedly fatal point where Mr Ahmed is accused of grabbing a kitchen knife and stabbing 29-year-old Mrs Elahi in the chest.

As she struggled with her catastrophic injuries, Mr Ahmed then called 000 to report what had happened.

Just before 10pm, police arrived and arrested Mr Ahmed – with blood splattered on his grey tracksuit pants – before covering his hands with evidence bags outside his Campbell Street unit block.

At the same time, paramedics worked furiously to save Ms Elahi but she died at Westmead Hospital.

It is understood the pair had been married for five years and moved to Australia from Bangladesh as many years ago.

Mrs Elahi's alleged murder on Saturday marked the second domestic-related death in NSW in a 24-hour period.

Irish national Daithy Ian Walsh, 29, was found with a stab wound to his neck following a fight outside his Padstow home in Sydney's south west early on Saturday morning.

The father-of-three's fiancee, Cathrina Ann Cahill, was later charged with his murder.

The Irish national chose not to appear on Sunday in Parramatta Bail Court, where her sister watched on from the public gallery.

Dressed in prison-greens, Mr Ahmed also chose not to apply for bail in court on Sunday.

Appearing via audio-visual link, his lawyer Zemarai Khatiz told the court his client was in a "very distressed state".

Mr Ahmed is expected to make a bail application on Monday.

Outside court, Mr Khatiz claimed his client learnt his wife was having an affair before her death.

"My client is in a very distressed and emotional state at the moment," he said.

"The deceased was having an affair, he found out about it and the relationship came to a very tragic end.

"The issue at trial will be whether he had the relevant intention at the relevant time."

Mr Khatiz said there had been no history of violence in the past.

Neighbours said they also had never heard or seen any signs of violence between the couple.

"I have never seen them fighting, they were just normal partners," Aditya Rana, who lived in the unit block, said.

Mr Ahmed's case was adjourned to Parramatta Local Court on Monday.