Indicted Galleon hedge fund founder Raj Rajaratnam faces expanded charges of insider trading and allegations that he earned $36 million in illicit profits, double the amount previously alleged, U.S. prosecutors said on Tuesday (Jan 05).

The government, pursuing what it has described as the biggest hedge fund insider trading case ever, signaled its intention to add to charges against billionaire Rajaratnam in a memorandum asking a Manhattan federal court judge to revoke his bail, Reuters reported.

Prosecutors said that while the indictment in December alleged that Rajaratnam was responsible for illicit profits of $17 million, at this time the government believes that the total illicit gains attributable to Rajaratnam's illegal trading are at least approximately $36 million.

The memorandum went on to say that the government plans to file a superseding indictment "that will expand the charges set forth against Rajaratnam in the current indictment."

It said those would include insider trading between March and July 2006 over an acquisition of ATI Technologies Inc by Advanced Micro Devices Inc. It said the information came from an unidentified source "to whom Rajaratnam began making large payments in exchange for inside information in or about 2004," reported Reuters.