Naked man ran through crowded train carriage
A man stripped and ran naked through a crowded train travelling between York and Middlesbrough.
CCTV footage of the streaker has been released by British Transport Police (BTP) in a bid to trace him.
Det Con Wayne Green said the man appeared to have stripped as part of a joke.
But he condemned the behaviour, which he said was "distressing" for many passengers, and appealed for anyone who recognised the man to come forward.
The streak happened between York and Middlesbrough last Friday at about 20:30 BST.
Det Con Green said: "The man stripped off his clothes and ran up and down the aisle completely naked.
"The man clearly thought this was fun and a joke.
"In reality, this was completely unacceptable and inappropriate behaviour which was clearly distressing for many of the passengers on board what was a busy service."