The hunt is on to find a cowardly thief who posed as a Good Samaritan in order to steal an elderly woman’s necklace.

Detectives have released a CCTV image of the suspect following the shameless act in North Wembley train station.

The 81-year-old victim was approached by a man who offered to carry her shopping as she travelled on the escalators towards platform two in the station.

After she politely declined he snatched the gold chain from her neck and ran off towards platform one of the station on May 18.

Detective Constable Mike Baker, from British Transport Police, said: “This was an utterly despicable theft from an elderly, frail and vulnerable woman who was clearly unable to defend herself. Fortunately she was unharmed but was still left very shaken by what took place.”

“If you recognise this man and think you can tell us who he is, we want to hear from you.”

Anyone with information is asked to contact British Transport Police on 0800 40 50 40 quoting background reference B9/LUA of 23/05/2012.