He is one of the wealthiest men in America with an estimated net worth of $1.3 billion and he was a major contributor to the campaigns of Hillary Clinton and also the single largest known U.S. contributor to a charity linked to the LTTE.

The case against Rajaratnam and five others alleges they netted over $25 million in profits. This was the first time a court authorized wire taps be used in a hedge fund case.

Rajaratnam gave more than $3.5 million to the Tamil Rehabilitation Organization (TRO), whose assets were frozen by the U.S. Treasury Department in Nov. 2007 because of its alleged ties to the Tamil Tigers.

According to documents filed with the IRS, Rajaratnam's contributions to the TRO were made in 2005 and 2006 through a separate charity, which he founded in the wake of the tsunami which hit Sri Lanka in Dec. 2004.

Despite its stated relief efforts, the Treasury Department described the TRO charity as "a front" for Tamil Tigers fundraising and procurement in the United States.

"TRO passed off its operation as charitable, when in fact it was raising money for designated terrorist group responsible for heinous acts of terrorism," said Adam Szubin, director of the Treasury's Office of Foreign Assets Control at the time.

Brigadier Udaya Nanayakkara, spokesman for the Sri Lankan Defence Ministry, said that the government had been monitoring Mr. Rajaratnam for several years.
He alleged that Mr .Rajaratnam had sponsored the Tamil Tigers for several years with “many millions of US dollars”.

The government of Sri Lanka has stressed that it would provide US authorities all the support it needs in the investigation.