Transit and Public Safety Command Assistant Commissioner Chris O'Neill, 60, remains in hospital with head injuries, following the assault near Heyington Railway Station in Toorak on Saturday afternoon.

Police are hunting two men who got off a train at about 5.30pm before kicking and punching Mr O'Neill in the head and chest.

Earlier, the men were spoken to by train staff over anti-social behaviour before they left the station.

Detectives have released images of two men they want to talk to about the assault and are expected to release security footage later on Monday.

One of the men was wearing a red baseball cap, grey jumper and black shorts.

The other was wearing a white baseball cap, a grey jumper and cargo pants.

Anybody with information is asked to contact Crime Stoppers on 1800 333 000.