The scheme that allowed Bernard Madoff to misappropriate $65bn in investor funds combined a single IBM mini-computer with a complex system of hiding the truth from authorities, according to a complaint filed on Tuesday by the Securities and Exchange Commission.

The SEC complaint, filed against Mr Madoff’s right-hand man, Frank DiPascali, outlined the rudimentary ploys designed to fool ­investors and SEC attorneys who reviewed Mr Madoff’s operation between 2004 and 2006.