Story highlights Robbers may have taken advantage of a four-day holiday weekend

Estimates of the value of the items taken rage from hundreds of thousands of pounds to 200 million pounds

The heist took place in a historic heart of London's jewelry business

London (CNN) The Hatton Garden heist, as it will surely come to be known, was every safe deposit box holder's nightmare, every movie director's dream.

Thieves using heavy cutting equipment and rappelling gear broke into the vault of an esteemed 60-year-old safe deposit company in the heart of London over the past holiday weekend, possibly taking advantage of as many as four days to rifle through an uncounted number of safe deposit boxes. And they reportedly got away with hundreds of thousands of pounds worth of gems and cash -- even, in the educated guess of one former police official, as much as 200 million pounds, or $300 million.

Police were offering few details Wednesday of the robbery at Hatton Garden Safe Deposit Ltd. Detectives on the scene were carrying out a "slow and painstaking" forensic examination, police said in a statement.

"Officers anticipate the process to take approximately two days," the statement said. "At this stage it is believed that approximately 60-70 safe deposit boxes were opened during the burglary. Officers are working closely with Hatton Garden Safe Deposit Ltd to establish the identities of those affected. Police will be contacting victims directly as and when they are identified."

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