Total claims have now reached £200 million, which is a huge leap from the £70 million that was initially feared missing. An unnamed source from a firm of private investigators told the Times newspaper that claims could even exceed £300 million.

The 45 year-old financier is thought to be residing in London clinic, The Priory, suffering from stress.

In his absence, he has been declared bankrupt and is now being investigated by insolvency experts Deloitte, as well as the Serious Fraud Office and Metropolitan Police, over the missing funds.

The high-flying financier, who has been described as a director, adviser and shareholder of a string of firms, became a trusted adviser to the wealthy, after developing a reputation for being a “smooth operator” with excellent contacts.

Various clients claim they entrusted him with millions of pounds, with some saying they have lost over £30 million. An investigator said that although Mr Levene wasn’t another Madoff, he had seemingly “taken money off people and invested it in far riskier things than they thought it would be.”  

His advisory business began to unravel last year when his clients started asking for returns on their investments as the economic downturn worsened.

It has been reported that one foreign investor seeking repayment hired “several large gentlemen” to abduct Mr Levene and take him to a warehouse where he was forced to sign documents transferring money.

A partner at Deloitte, Louise Brittain, who is in managing the troubled adviser’s bankruptcy, has said: “Over the next few days, we will be trying to discover the scale of creditors’ losses and what assets are left. This is a complex case that involves gathering evidence in a number of different countries.”