Police are chasing a man over a serious assault at St Kilda.

Investigators were told the man was seated outside at a venue on Acland Street with a 36-year-old female in the early hours of November 12.

The man was asked by staff to leave due to poor behaviour.

He’s then assaulted a 46-year-old man and the woman, with the woman receiving serious head injuries in the attack that required surgery.

Investigators have released an image of a man they believe may be able to assist with their enquiries.

He is perceived to be 20-30 years old, with light brown hair and an English accent.

Anyone who witnessed the incident or who recognises the man is urged to contact Crime Stoppers on 1800 333 000 or file a confidential report at www.crimestoppersvic.com.au