Three men and a woman have been arrested in connection with a smash-and-grab raid at the Dorchester Hotel.
The famous luxury hotel, owned by the Sultan of Brunei, was hit in the early hours of Thursday morning by a gang of robbers who smashed their way through the doors using sledgehammers before stealing a vast quantity of watches and jewellery.
Six men pulled up outside the hotel on motorcycles before three of the raiders broke into the hotel and stole the gems from the display cabinets.
The men then fled the scene on the waiting mopeds.
At 2.30pm police later arrested two men, aged in their 50s and 20s, and one woman, 50, at an address in Kings Cross on suspicion of conspiracy to handle stolen goods.
Another man in his 20s was also arrested on suspicion of conspiracy to rob and conspiracy to handle stolen goods.
All four were taken to a London police station where they remain in custody.
It is the second time in a month the hotel has been hit by a 'well-planned heist'.
A Met Police spokesman said: "Enquiries continue to ascertain if there is a link between the robbery on 10 July and another at the same location on 10 June."