Con artists posing a police officers have been targeting visitors around the South Bank and London Bridge.
Metropolitan police officers have stepped up patrols after criminals claiming to be plain clothes officers began targeting tourists near attractions such as the Globe Theatre and the Shard.
They demand to see people’s identities and then steal cash from their wallets.
The Met said it had recorded six incidents between March and May.
A spokesman told the Evening Standard: “The bogus officers approach their victims - they inform them that they are police officers in plain clothes and need to see their wallets. At this point they take the cash from the victims and leave.”
The bogus officers are reported to be Eastern European and there have been similar incidents reported in Westminster, Lambeth, and near Tower Bridge.
A spokesman advised that no police officer would ever demand money and none would ever ask for a PIN number.