LOS ANGELES, Feb. 6 - Irwin Schiff, the nation's best-known promoter of claims that no law requires the payment of income taxes, suffers from delusions including a fantasy that he alone can properly interpret the tax laws, according to papers that he had his lawyers file in Federal District Court in Las Vegas.

The mental health claim is also a ruse, according to an e-mail message sent on Tuesday to Mr. Schiff's thousands of supporters by his girlfriend, Cindy Nuen. She wrote that this defense is the only way for Mr. Schiff to escape fraud penalties because, she wrote, his lawyers are "scared" to tell judges that "the income tax law is meritless and frivolous."

Mr. Schiff's personal psychiatrist, Dr. Luis Carlos Ortega of Las Vegas, wrote last year, ... that Mr. Schiff has suffered from paranoid delusions about the tax system for decades.

...Court of Appeals for the Ninth Circuit in San Francisco is scheduled to hear oral arguments on Tuesday on whether Mr. Schiff can be barred from selling his book "The Federal Mafia: How the Federal Government Illegally Imposes and Unlawfully Collects Federal Income Taxes."