Anthony Constantinou was convicted of one count of fraud, two counts of fraudulent trading and four counts of money laundering at Southwark Crown Court on Monday.

The 41-year-old did not attend the later stages of his seven-week trial, and an international arrest warrant has been issued to trace him.

Constantinou, of no fixed address, ran Capital World Markets (CWM) which offered investors returns of 60% per year on what he claimed were risk-free foreign exchange (FX) markets.

CWM operated from late 2013 to early 2015, and Constantinou told investors they would receive returns of 5% per month and those who introduced investors to CWM also received a cut.

In the early stages of the scam, investors were told there was an initial minimum investment of £50,000, but this increased to £100,000 in the later stages.

Prosecutors told the court those who signed up were taken in by CMW's high-end City of London offices and high-profile sports sponsorship deals, including one with Premier League club Chelsea.

Despite significant funds from more than 250 known victims, the money was not being invested in foreign exchange and the purported returns were being paid back to the investors from their own and others' invested capital, City of London Police said.

Investors were told similar stories about what would happen to their money and how the scheme worked: only 10% of capital was risked and the remaining 90% was held safely in a "segregated account" in Germany.

Investors were reassured the risk was further reduced, with the 10% being protected by matching funds in CWM and a guarantee from Constantinou himself.

Evidence suggested that despite others having key roles in the scam, Constantinou was the only person who knew what was really going on with the company, City of London Police added.

The investigation into Constantinou and CWM began in 2014.

After an initial investigation, police officers made the decision to stop the scheme before it collapsed to preserve as much money as possible for investors and to stop further people falling victim to the scam.

Officers searched the Heron Tower offices of CWM in the City in March 2015 and arrested Constantinou.

Following the search, an investigation of CWM's finances showed extravagant spending from clients' funds, including £3m spent by Constantinou on lifestyle events, including his wedding and a CWM launch party.

Detective Inspector Nichola Meghji, from City of London Police, said: "Throughout this lengthy investigation, Constantinou has continued to try to deceive officers and deny any wrongdoing. In a further move to deny any involvement in this case, he decided to stop attending his trial.

"We are glad that the jury has seen through his lies and unanimously found him guilty."

The court heard last week that Constantinou was recently arrested in Bulgaria with fake identity documents but was released and remains at large.

He is due to be sentenced in his absence on 9 June.