These shocking images show an 'idiotic' superhero wannabe 'surfing' on top of a Chester-bound train travelling at speed.
The man, who called himself the Silver Shadow when questioned by ticket staff, was captured carrying out the dangerous stunt on a Wirral line Merseyrail service earlier this month.
Police have now released images of the incident, and a man they would like to speak to in connection with it.
At 1.30pm on December 11 a man crept between two carriages at Rock Ferry station.
Seven minutes later he was spotted on CCTV riding on top of the train as it travelled through Bromborough Rake station. He was even seen waving at passengers, many of whom will have either been heading to Chester where the line terminates or changing at Hooton for the Ellesmere Port service.
He then got off the train at Bromborough and was briefly spoken to by booking office staff.
Concealing his face, the man told staff he was called the 'Silver Shadow' and had travelled to Wirral from Birmingham.
Investigating officer PC Andrew Richardson said: “Even attempting to get on the top of a train is a nonsensical and idiotic thing to do.
“The man concealed himself between two carriages above electrified rails and so one slip could have easily killed him and endangered the lives of those on the train.
“This isn’t cool, it isn’t funny, it’s dangerous and we will not stand for it.
"If you recognise the man in these pictures, please get in touch.”
Anyone with information is asked to contact British Transport Police on 0800 40 50 40 or text 61016, quoting 141 of 21/12.