A French investment manager who ploughed €1.5 billion into Bernard Madoff's fraudulent scheme was found dead on Tuesday in his New York office.

An autopsy was to be performed on Thierry de la Villehuchet, 65, who was found dead by a security officer of the Madison Avenue building that housed his Access International investment business, according to the New York police department.

Villehuchet, co-founder and chief executive of Access International, which invested funds for the cream of Europe's high society, was both an investor in and apparent victim of Madoff, a former Wall Street pillar now accused of running a multi-billion-dollar pyramid scheme.

Villehuchet was managing some €2 billion for European clients, of which three quarters had been invested with Madoff when the scandal broke, a friend of his said.

Officials at Access, which employs 26 workers and managed $3 billion before the scandal broke, would not comment.

Prosecutors say that Madoff, 70, has confessed to losing upwards of $50 billion over years of running a pyramid scheme, where new investors were secretly fleeced to pay returns to earlier investors, in what may be the biggest scam in the history of Wall Street.

Madoff, former chairman of the Nasdaq stock market, is currently free on bail of $10m as police continue their probe.