Evidence of paedophilia, firearms possession, drug trafficking and prostitution have been uncovered by police conducting an investigation into the criminal use of safety deposit boxes.

Police are now conducting over 1,000 spin-off investigations and believe they have inflicted a substantial blow to global crime networks.

Among the items discovered in the 3,554 seized boxes were millions of pounds, euros and US dollars in cash; illegal elephant tusks; drugs including ketamine and pure cocaine; forged passports and numerous firearms.

Detective Chief Inspector Mark Ponting, leading the investigation, said: “Operation Rize has been a great success. We have recovered £35 million of cash, the majority of which is from the proceeds of crime.” As part of the probe, 700 box holders are being investigated for tax evasion.

Two prominent members of the Jewish community were among 11 people arrested when more than 300 police officers raided three safety deposit depots in Hampstead, Edgware and Mayfair in June last year.

Leslie Sieff and Milton Woolf, directors of Safe Deposit Centres Ltd, were arrested on suspicion of money laundering and are bailed to a date in May pending further enquiries. They have not been charged. Both men have lived in London since the 1980s after moving from South Africa.

Mr Sieff is a former treasurer of New London Synagogue, while Mr Woolf was head of the search committee seeking to appoint a new rabbi at the shul after the death of Rabbi Louis Jacobs.