Image released after Melbourne pier attack

An image of a man wanted for questioning over a midnight tomahawk attack on a Melbourne fisherman has been released by police.

The 44-year-old victim was hit in the back of the head by another man on Beaumaris Motor Yacht Squadron pier on July 26, police say.

Detectives have release a composite image of a man described as Caucasian, aged about 20 and wearing a hoodie who they want to speak to about the incident.

Three men unloading fishing gear from a vehicle at the yacht club gate at the time and spoke to the victim after the attack are also urged to come forward.