Police are clamping down on an illegal street game that “tricks” people into parting with their cash.

Officers in Harrow are working with Harrow Council to stop the ‘cup and ball’ game spreading in the borough.

A ball is placed under a one of three cups, which are then moved around a mat, before participants are encouraged to guess where it ends up.

‘Marks’ are used to give the illusion of an easy win, but sleight of hand tricks mean those playing are rarely successful.

Inspector Tanya Sprunks, from Harrow neighbourhoods, explained the game is popping up in Harrow town centre and people should steer clear.

She said: “We are aware that members of the public are being encouraged to take part in playing ‘cup and ball’, which is becoming more apparent in Harrow now and entices people to part with their money.

“Don’t be fooled – these tricks are designed to cheat people of their cash. If you see anyone operating games such as ‘cup and ball’ within Harrow, please alert officers or call 101.”

Police are working with Harrow Council to catch the culprits and advise people against being drawn in by the game.

Cllr Krishna Suresh, responsible for crime and community cohesion, said it is important to target popular areas – such as shopping centres – where the scammers feel they can have more success.

He said: “We are advising shoppers not to be tricked into playing this addictive game, which is hugely popular and is a complete scam.

“A hand movement is used to remove the ball from the cup, so that unsuspecting people lose their cash, without realising what has really taken place.”

The game has been a longstanding problem in London, particularly in areas popular with tourists.

Over the weekend, the Metropolitan Police’s Special Constabulary confiscated cup and ball equipment on Westminster Bridge.