A thief stole £15,000 from a dozing passenger on a Virgin train.
The money, which was in a bag, was taken from on board a Virgin Trains service from Liverpool Lime Street to Runcorn.
British Transport Police said the incident happened at about 9am on Saturday 1 March, as the victim, a 45-year-old man from Ellesmere Port, travelled toward Stafford.
DC Dominic Wilcox said: "The man had planned to travel to Stafford to purchase a car – and was carrying the cash in a bag.
"The victim dozed off and as the train arrived at Runcorn, a man grabbed the bag from the seat next to the victim and quickly left the train."
Enquiries conducted following the incident have enabled detectives to isolate the image of a man they believe has key information.
DC Wilcox added: "We are convinced the man captured has vital information about the incident and call on anyone who recognises him to come forward.
"We would also like to hear from anyone with further information about the theft."
If you have any information about the incident, please call British Transport Police on 0800 40 50 40 or ring Crimestoppers, anonymously, on 0800 555 111. In all calls please quote log PSUB/B6 of 9/5/14.
In 2012, a thief who stole a passenger's smartphone on the subway in Budapest was captured by a commuter who filmed the moment he struck.
The criminal calmly waited for the next stop before quickly grabbing the phone from a woman and darting between the sliding doors of the car before they shut again.
According to the Daily Mail, the bystander who made the video in Budapest, Hungary, filmed the man because he was seen looking suspicious.
Gizmodo reported that the video went viral in Hungary and the thief was quickly caught as a result of the publicity.
A Budapest police spokesperson said the man was later arrested and interrogated before he confessed.
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