An Irishman has died after being stabbed at a restaurant in Sydney, Australia.

Keith Collins, who lived in Terrigal, New South Wales, was attacked while dining with a woman in Hornsby Mall last night.

The woman, Jobi Pilapil, was also injured in the incident, which occurred at about 9.30pm local time. 

Ms Pilapil, 38, suffered stab wounds to the chest and arm and was taken to hospital after escaping the restaurant and collapsing at a nearby shop.

It is believed Mr Collins, 53, was from Dublin but had been living in Australia for some time.

The Department of Foreign Affairs said it was aware of the incident but that it had not received any request for consular assistance.

A 44-year-old man has been charged with murder and attempted murder. 

Detective Acting Superintendent Damian Henry told reporters the relationship between the three people will form part of the police inquiry.

"We're yet to establish if there's a domestic relationship between the three parties,"  he said.

"We believe that there might be a domestic relationship between the female and the (charged man)."

One witness to the attack said:"The guy jumped over the counter and stabbed him with a glass bottle." 

It has yet to be confirmed if a knife or bottle was used in the attack and a number of items were taken from the scene for forensic examination.

Mobile phone footage from diners and other shoppers in the centre will also be scoured as part of the investigation.

Footage of the suspect being arrested shows a Taser-wielding officer demanding the man drop a backpack and kneel on the ground before being handcuffed.

The alleged attacker was refused bail and was expected to face Hornsby Local Court.