A disabled woman was sexually assaulted by a man with a knife at Epsom station on Saturday night.

The assault happened just after 10.15pm, on June 21, when the woman, who is in her 20s, was on the stairs in the station.

She was approached by a man who touched her inappropriately and then ran off. 

It is understood that the woman's partner was also there, along with a young boy, and he gave chase to the pervert.

He pursued the man out into the street and is believed to have only stopped when he saw the man was holding a knife.

Police described the attacker as black, slim, in his late 20s or early 30s, and between 5' 9" and 6' tall.

He was wearing blue jeans and a black jacket.

DC Dave Peek, of British Transport Police (BTP), said: "Thankfully the victim wasn't injured during the incident, but was left extremely shaken and upset.

"I am determined to trace the man responsible and call on anyone with information to get in touch."

Anyone with information should call the BTP on 0800 40 50 40 or Crimestoppers, anonymously, on 0800 555 111, quoting log 626 of 21/6/14.