Police are appealing for information after a man exposed himself to a female passenger on board a c2c train.
It took place on the 12.40pm train from Fenchurch Street to Shoeburyness on Saturday, January 10.
The woman got on at West Ham and as the train passed through Barking and Upminster, she noticed the carriage becoming empty.
When she stood up to get something from her pocket, she saw a man sitting on the seats behind her who started masturbating.
He left the train at Benfleet.
Officers from British Transport Police have released CCTV footage of a man they believe has vital information.
If you recognise him, or were on the train, call 0800 405040, or text 61016, quoting reference ESUB/B3 of 27/01/15.
Alternatively, call Crimestoppers anonymously on 0800 555 111.
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