Two agency staff working at the security firm targeted in Britain's biggest robbery have been arrested, prompting the suspicion that the raiders had inside help.
The man and woman, who were sub-contracted to work for Securitas, were questioned about the £53m robbery at Tonbridge in Kent, police said.
Police suspect that some gang members have fled abroad with a significant amount of the stolen cash. So far, detectives have recovered about £20m.
The ease with which the gang of robbers kidnapped a Securitas manager, his wife and son, broke into a cash warehouse and stole £53m last month, led detectives to believe they had information from an insider at the depot. That suspicion strengthened yesterday when police disclosed that they had arrested a man who had been working for Securitas, and a woman who was a former employee. The two suspects were released on bail.
Adrian Leppard, Assistant Chief Constable of Kent, said: "Two members of staff, a man and a woman, who are agency staff sub-contracted to Securitas, have been arrested and released on police bail."
The police investigation is widening beyond Kent and includes sending officers abroad to follow leads and question suspects.
Mr Leppard said that his officers were studying film from surveillance cameras in ports, as well as vehicle number plate recognition systems, to try to discover whether any robbers left Britain in the hours after the robbery. A van with £1.3m in cash, guns and balaclavas used in the robbery was found abandoned near the Channel Tunnel.
Mr Leppard said: "We have got a fairly wide inquiry basis at the moment that looks at a range of people in a range of areas; a lot of them in this country, but not all."
One of the people police have spoken to is Nigel Reeve, who drove to Spain in a white van two days after the robbery on 22 February. Mr Reeve, who denies wrongdoing, owns ENR Cars, a vehicle repair business, in Welling, south-east London, where £9m of the stolen cash was found. A source said Kent police had spoken to Mr Reeve, and he would be questioned again.
Police are also examining hundreds of hours of CCTV footage of the various escape routes from the Tonbridge area. The armed gang was filmed loading the cash into a white lorry at the Securitas depot, but the police have not released the images.
The investigation team is working with international financial institutions to track the stolen banknotes, some of which are traceable.
The senior officer said the £2m reward offered to persuade criminals to turn in the robbers had produced a number of useful calls. He said: "Two million pounds stimulates people. There was an upturn in intelligence coming forward."
He added: "The scale of this investigation and pace of the inquiry has put the criminals under enormous pressure. Although this was a well-planned enterprise, the pace of the investigation has caused the robbers to make mistakes."
* Four men and a woman have been charged over the £53m robbery
* Ten people, including two Securitas depot workers, have been arrested and bailed
* Two people have been questioned and released with no further action
* About £20m has been recovered, £1.3m of which was found abandoned in a van in a car park near Ashford
* About £300,000 was found near Elverden Farmhouse, Staplehurst, Kent. The property is owned by a car dealer charged with conspiracy to rob
* £9m was found at the back of a vehicle repair business in Welling, south-east London
* About £10m was found in a domestic garage in Southborough, near Tunbridge Wells. It is understood to be linked to one of the people chargedReuse content