The £35m deposit box sting

Some 700 people are being investigated by Scotland Yard for tax evasion following raids at three London depots.

These included "several" described as "ghosts" - people who had never paid tax in their lives. The cash was part of a total £35million haul which was kept in the centres by organised crime gangs and individual criminals.

Guns, images of child pornography and drugs were also seized as part of a series of raids by the Metropolitan Police specialist crime group. So far £20million cash has been seized by the courts as the suspected proceeds of crime while the £15million has been referred to Customs and Revenue officers.

Offices in Edgware, Park Lane and Hampstead, all owned by Safe Deposit Centres Limited, were raided by police in June last year. About half of the 7,000 or so boxes have now been linked to crime sparking more than 1,000 separate investigations.

These range from murder to benefit fraud and illegal smuggling of elephant ivory. Three men have been jailed and 11 charged with criminal offences.

Detective Chief Inspector Mark Ponting said Operation Rize - the first crackdown of its kind to target criminals using secure storage - had resulted in about 40 arrests.

He said: "Some of the organised criminal networks that placed their funds in the premises never expected to have them recovered by the police. It has had an impact globally."

Police said the boxes were searched after intelligence suggested they were linked to paedophilia, firearms, people trafficking, prostitution and money laundering.

Various items were seized, including millions of pounds in cash, gold and class A drugs. Forged passports - one boxed contained 17 different sets of official documents - and elephant tusks worth £40,000 were also confiscated.

Detectives are investigating a box, not accessed for more than 10 years, that contains a hammer, chisel and pipe wrench. "There is clearly a story behind these items - to retain it within a secure facility heightens the suspicion," said Mr Ponting.

He added: "There's very little in terms of cash that is held genuinely."

Last week Leon Gavin, 33, was jailed for five years after police found drugs and a 9mm Glock handgun in a safety deposit box he had rented.

Police also appealed for information about the whereabouts of John Derriviere who is wanted after officers discovered a Brocock firearm and nine rounds of ammunition in his box. More than 60 officers are working full-time on the inquiry, expected to cost over £1million.

But Mr Ponting said the operation was paying for itself. "We are taking the money back to the Treasury and putting it back into the public purse."