British Transport Police have released CCTV images of a man they want to identify following a series of alleged sexual assaults on trains travelling between London and Essex.

Detectives are investigating three incidents involving women on board trains to Essex over a period of several months.

The first incident is reported to have happened in March, when a woman was allegedly sexually assaulted and subjected to an attempted sexual assault.

During one of the incidents, the suspect is understood to have left the train at Westcliff-on-Sea.

Months later, shortly after midnight on 5 July, another woman was allegedly sexually assaulted while travelling on a train from London to Benfleet.

British Transport Police have now issued CCTV images as detectives work to identify a man who they believe may have information that could assist the investigation.

A BTP spokesperson said: “Detectives investigating three sexual assaults on board trains to Essex have released these images in connection.

“Detectives believe the man in the images could have information that may assist their enquiries.”

Anyone who recognises the man, or has information that could help the investigation, is asked to text British Transport Police on 61016 or call 0800 40 50 40, quoting Operation Valhalla.

Information can also be provided anonymously to Crimestoppers on 0800 555 111.