Police are hunting a man who groped a 28-year-old woman on a train.

The woman was travelling on a train from Hounslow to Clapham when the incident happened.

Initially the man sat near the victim and tried to engage her in conversation, but when she got up from her seat he put his hand under her skirt and grabbed her bum.

Investigating officer Detective Constable Vanessa Cottington of the British Transport Police said the man, described as white and in his mid 20s, boarded the train at Kew Bridge before 8.55pm on November 13.

The man is between 5ft 6in and 5ft 10in, of slim build, with short dark hair. He was wearing a dark coloured top and jeans.

Police have released CCTV images of a man wanted for questioning in connection with the incident.

"The onboard CCTV image is very clear, and we're hopeful that a member of the public may recognise the man. We're eager to identify him as part of this ongoing investigation," said D Con Cottington.

Anyone with information should call the BTP on 0800 40 50 40 or the witness appeal line on 020 7391 5275 quoting B5 of 30/01/2008