A Sydney father of six has died in hospital surrounded by his family after allegedly being bashed on his morning walk, and a man is in custody charged with his murder.

Corum Anthony Ash, 45, was arrested on Monday night following a public appeal by police.

Police allege Ash assaulted a 74-year-old man out for a morning walk in Sydney’s south-west on Saturday morning.

The man, Quang My Pham, was found unconscious on Orchardleigh Street, Yennora, about 4.40am and taken to Westmead Hospital in a critical condition.

“Unfortunately, yesterday that male passed away in hospital surrounded by his family,” NSW Police Superintendent Craig Middleton said.

“This is a real tragedy for the family involved.

“He’s a husband and a father to six children, and at the moment they’re dealing with an enormous amount of grief, and our condolences go out to that family.”

Ash has been charged with murder and cause wounding or grievous bodily harm with intent to murder.

Investigators had been unable to speak to Pham in hospital due to his condition, but identified Ash as the alleged perpetrator on Sunday after canvassing at the scene.

It’s believed to have been a random attack with an unknown motive, Middleton said.

“There’s certainly no connection between our victim and the offender,” he said.

Police raided a property at Carlingford on Sunday afternoon and seized “clothing and some items” believed to be related to the incident, Middleton said.

An appeal to locate Ash was then issued before his arrest at the same address on Monday night.

Ash did not apply for bail and was formally refused in Parramatta Local Court on Tuesday.

He is due to face the same court again on September 10.

Start the day with a summary of the day’s most important and interesting stories, analysis and insights. Sign up for our Morning Edition newsletter.

Jack Gramenz is a breaking news reporter at The Sydney Morning Herald.Connect via email.