Police have named a suspect wanted in connection with the robbery of £4.1m worth of jewellery from a salesman.
The victim suffered serious injuries in the attack at the Elmsleigh Centre car park in Staines, Surrey, on 13 May.
Surrey Police said the salesman, who worked for upmarket US jewellers Le Vian, was attacked by a gang which escaped with a multi-million-pound haul.
Two men have been arrested and officers named Ciro Troyano as a third suspect.
Surrey Police has refused to reveal details of what detectives said was a violent robbery, citing "operational reasons".
But it said the salesman was attacked as he left his car in the multi-storey car park between 07:30 and 08:30 BST.
The gang fled with a bag containing jewellery and some personal belongings made by Le Vian but police would not say whether the victim was wearing any of the property stolen.
The spokesman said he was treated in hospital for serious injuries but had since been released.
Police arrested two men, aged 39 and 48, in London earlier but are appealing for information to track down Mr Troyano, who they say is wanted on suspicion of conspiracy to commit robbery and assault causing grievous bodily harm.
He is described as 5ft 6in tall, medium build and has links with south and south-east London.