A gang of six men pulled up on mopeds outside the Dorchester Hotel in wealthy Mayfair in central London in the early hours yesterday morning and smashed display cabinets, stealing watches and jewellery.
The thieves managed to shake off pursuing officers just over a mile away in Shaftesbury Avenue.
One of the bikes hit a 25-year-old woman in Cambridge Circus as the gang fled, leaving her with leg injuries.
DC Alex Flanagan said: "This was a well-planned robbery. I am keen for those with any information to come forward and assist us with our investigation."
It follows a number of similar robberies that have taken place in London's West End where thieves have arrived on bikes and tried to smash their way into jewellery stores.