A TEENAGE boy is being sought by police after he carried out a sex act on a train while sitting opposite a woman.

British Transport Police have urged anyone who witnessed the incident, which occurred on March 10 on the 2.28pm service from London King’s Cross to Edinburgh Waverley, to contact them.

Police said the teenager sat opposite the woman after the train stopped at Newcastle.

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Then between 5.50pm and 7.30pm as the train passed through the Scottish Borders she saw him carrying out the sex act.

He left the train at Edinburgh.

The boy is described as being aged 17 to 18, white, 6ft, of proportionate build, with sandy hair shaved at the side and longer on the top.

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He was wearing a 1990s-style multicoloured, patterned bomber jacket with black across the shoulders, a bright purple T-shirt and loose-fitting blue jeans.

Anyone who witnessed what happened or has any information about it is being asked to contact British Transport Police by calling 0800 40 50 40 or texting 61016, with reference 2300028810.