UNDERCOVER police posed as potential victims in an operation to tackle luxury watch robberies.
The officers walked the streets at night hoping to run into gangs who target designer timepieces.
In one incident, the thieves approached a lone officer, tried to befriend them, before ripping their watch off their arm.
A hidden police back-up team then emerged to capture the crooks.
The Met Police operation in central London resulted in 27 arrests and 21 convictions.
Commander Ben Russell said: “Many of these men have long offending histories and cause misery.
“In this scenario a police officer was approached by a man and asked if he wanted to visit a brothel.
“He was then taken on a walkaround through quiet side streets, during which time he was unknowingly being followed by four other men.
“When the time is right, the men then swarm the officer and rob him.
“Other police officers appear out of nowhere, tackling the criminals to the ground.”
It followed a series of high-profile robberies.
In April 2022 ex-boxer Amir Khan had his £72,000 watch stolen at gunpoint in East London.
