POLICE have released a CCTV image of a man they believe witnessed a sexual assault on a Southend train.

A 18-year-old woman was sexual assaulted by a man she was traveling with on a Southend train bound for Fenchurch Street.

The incident took place between 8.55pm and 10.10pm on 12 March.

Detective Constable Andy Parkinson said “Following the report, we examined CCTV from the train bound for Fenchurch Street and had uncovered images of three witnesses who we believed may have more information about what happened and can help us with our investigation.

"Two witnesses have been ruled out from our enquiries. Officers are still looking to speak with the man in the CCTV image who they believe can help in the investigations.

"I would urge any witnesses to come forward so we can establish the full circumstances behind this concerning incident.”

Anyone with any information should contact British Transport Police on 0800 40 50 40 or text 61016 citing reference 490 of 14/03/2016.

Alternatively, details can also be given to the independent charity Crimestoppers anonymously on 0800 555 111.