Search for intruder after elderly Adelaide man dies in violent home invasion

Investigators are searching for an intruder who fatally attacked a 70-year-old man inside his home in Adelaide’s northern suburbs.

John Rielly, 70, was at his Virgo Street home when he was confronted by a man between 6.45am and 7am last Friday.

The intruder demanded Mr Rielly’s money, bank card and pin number, before fleeing.

Fifteen minutes later, the offender returned and assaulted the victim.

He was taken to hospital with broken ribs and died last night from his injuries.

South Australia police today released CCTV of a male youth in a black bicycle helmet at an ATM, who they believe has “crucial information” about the crime.

Authorities swarmed the Elizabeth South area today, after a black helmet was spotted.

A home five doors down from Mr Rielly’s was searched, however the occupants were given the all clear, police said.

Mr Reilly’s friends and family told 9NEWS they are desperate for the offender to be found.

“It’s dreadful, absolutely dreadful. I didn't think anyone could do that to an elderly man,” Moira Collins said.

“He didn’t deserve this, that’s for sure.”