By The Associated Press

NEW YORK - One of the richest men in the U.S. is defending himself against a massive insider trading case by saying he did not cheat and the government misled a judge to obtain wiretaps.

Billionaire hedge fund operator Raj Rajaratnam's (RAHJ rah-juh-RUHT'-nuhm) lawyers made the arguments in papers filed Tuesday in federal court in Manhattan.

The Sri Lanka-born Rajaratnam is among 20 people charged in a US$52-million insider trading case. The portfolio manager for the Galleon Group hedge fund remains free on $100 million bail.

Rajaratnam's lawyers say he based trades on information that was already public.

They also say the government misled a judge to surreptitiously tape phone conversations by Rajaratnam and others.

Prosecutors declined comment.