Security camera pictures have been released of two men wanted for questioning over a weekend bashing in the city, that's left a man fighting for life.

Twenty-seven-year-old Gary Ge was attacked in the early hours of Sunday morning, and remains in critical condition with a severe head injury.

Gary’s family and girlfriend are maintaining a bedside vigil at St Vincent’s Hospital.

Seven News has just obtained pictures from a premises on Pitt Street where the incident happened.

It clearly shows Mr Ge being punched in the head twice before he fell to the ground.

Police have released footage which shows a couple running, followed by the two men police want to talk to.

Officers believe the group may have argued with the victim after he asked them to stop taking photos of a drunk mate.

"My absolute hope is that these people will contact us and we can start to work through this matter with them," City Central Police Commander Mark Walton said.

Friends of Mr Ge have described him as a kind man.

"As a friend he was always kind to everybody. he always treats people the right way and I think this thing happened because he was too good to friends," mate Mike Wang said.

The first man is described as having a light complexion, aged in his late 20s, about 178 centimetres tall.

The second man is aged in his early 20s, with a solid build about 183 centimetres tall.