Four people have now been arrested in connection with an armed robbery during which a cash delivery worker is thought to have been pistol-whipped outside a Co-op.

The delivery worker’s cash box, containing about £45,000, was stolen during a routine stop outside the store in Tattenham Corner on January 30 at 10.30am.

A man in his 40s, from Battersea, was arrested yesterday on suspicion of conspiracy to commit robbery and money laundering. Another man in his 20s, who was arrested on suspicion of armed robbery, has been further arrested on suspicion of burglary and money laundering.

Both men have been released on police bail until July 23.

A woman in her 20s, from Battersea, and a man in his 20s, from Brixton, have also been arrested on suspicion of money laundering and released on bail until September 17.

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A close up picture of the car believed to have been used by the offenders

Since the armed robbery police have searched properties in Box Hill, Wandsworth and Battersea as part of an ongoing live investigation called Operation Jadeite.

In January a passenger jumped out of a cream Chevrolet and hit the cash delivery worker in the face with what is thought to be a handgun. The car was later found abandoned in North View Crescent.

Detective Chief Inspector Paul Rymarz urged witnesses and anyone with information or suspicions about someone they know to come forward.

He said: "This is a complex inquiry but I hope the four arrests which have made in connection with this incident go some way to reassure the public that we are carrying out a full and thorough investigation."

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A picture of a cash box similar to the one stolen

For information on Operation Jadeite visit http://tinyurl.com/OperationJadeite or follow #OpJadeite hashtage on Twitter.

Anyone with information should call Surrey Police on 101, quoting Operation Jadeite, or call Crimestoppers anonymously on 0800 555 111.