Officers investigating a sexual assault on a train are appealing to a potential witness to come forward. 

The incident took place on a train between Edinburgh Waverley to Falkirk Grahamston, British Transport Police (BTP) said. 

On Saturday, July 29 last year, a woman was sexually assaulted by a man who sat next to her on the 8.03pm service.

The man is described as white, in his early thirties, with dark short spiky hair, and a short shaved beard.

READ MORE: Woman assaulted and kicked onto railway tracks by fellow train passengers

He was wearing a black T-shirt, a grey Adidas hoodie and blue denim jeans with brown boots.

BTP officers are appealing to a woman travelling with a young child, who they believe may have witnessed the incident.

Anyone with information regarding the incident is asked to contact BTP by texting 61016 or calling 0800 40 50 40 quoting reference 130 of 16 January.

Alternatively you can call Crimestoppers on 0800 555 111.