Life support: Irish backpacker Gearoid Walsh who is fighting for his life after being attacked in Sydney

An Irish man is fighting for his life in an Australian hospital after being attacked in a Sydney beach suburb.

Gearoid Walsh, 23, was rushed to hospital Sunday when he stopped breathing following the attack at Coogee.

Walsh, who is now on life support, had only arrived in the country a month ago on a 12-month working visa.

His mother has flown out from Ireland to join him and another son and daughter who also live in Australia.

The police said they believed Walsh had got into an argument with a man at a takeaway food shop.

Detective Inspector Paul Simpkins said, "Initially, Gearoid left with his brother, but returned moments later and the argument continued."

"The man punched Gearoid who stumbled and fell, hitting his head on the ground."

Sydney police have released CCTv footage of a man they wish to interview in connection with the assault.

He is described as being of white/European appearance, 25 to 30 years old, 175cm tall, medium build, with short brown and slightly curly hair and a clean-shaven, round face.

The man wore a white T-shirt and jeans.

"This is a sad incident for the family," Inspector Simpkins said.

"Gearoid only arrived in Australia a month ago on a working visa and had been spending time between his brother's house in Brisbane and his sister in Randwick."