A Met spokeswoman said: “Police were called at 2.56am on Friday, April 26, to Sloane Street following reports of a smash-and-grab at a jewellers.
“A Transit van is reported to have driven into the shop front before a number of accompanying mopeds stole a quantity of items from the shop window.
“All those involved then fled. The Transit van was left at the scene.
“No arrests have been made. Inquiries continue.”
The Telegraph has contacted Tiffany & Co for comment.
Thieves have previously targeted the jewellers.
In October 2005, a suspected thief was killed after he was hit by a police car following an attempted raid at the store.