A tourist had a £115,000 watch ripped from his wrist in a "violent" robbery in Mayfair.
The 55-year-old man was staying in a hotel in the affluent central London area when he was pounced upon by three men, police said.
During the attack in Berkeley Square, the assailants tore the Breguet Tourbillion timepiece from his left wrist.
Footage shows three men fleeing the scene, in the direction of Park Lane, with the victim and his wife initially trying to chase them. The victim suffered a deep stab wound to his left arm during the incident, police said.
Scotland Yard has released a CCTV image of three men they wish to speak to in relation to the incident, which occurred around 3.30pm on June 9 last year.
Detective constable Eve Kelly said: "This violent robbery was committed in broad daylight, and it appears that the victim was specifically targeted for his watch.
"He and his wife were left shaken, and have since received counselling to help deal with the impact of this robbery.
“We have followed up numerous CCTV and forensic leads but unfortunately not made any arrests, and now we are hoping that the public can help put names to these faces.
"If you recognise any of these men we would urge you to get in touch.”
The suspects have been described as men in their 30s, of Mediterranean appearance and medium build.