Greg Wahl-Stephens / AP file Stanley Cohen, center, attorney for Mohamed Kariye, speaks to reporters on the steps of the Federal Courthouse in Portland, Ore., in 2003. Kariye was arrested after traces of explosives allegedly were found on his clothing as he boarded an airplane. The charges were dismissed, but Kariye pleaded guilty to making false statements in applying for state health insurance benefits and to Social Security fraud.

A Manhattan lawyer who has represented Osama bin Laden’s son-in-law, Hamas officials and other big-name defendants in terrorism cases was indicted Wednesday on federal charges that he failed to report more than $3 million in income.

The federal grand jury indictment in Manhattan charged Stanley L. Cohen with five counts of failure to file individual income tax returns for the 2006-2010 tax years and one count of wire fraud.

The government alleged that Cohen was paid at least $500,000 in fees each of those years but hid the money by having clients pay in cash or telling them to wire payments directly to American Express to pay his card bills.

The indictment said Cohen stored cash payments in a safety deposit box instead of putting them into a bank account and deposited legal fees into his personal accounts. It alleged that the schemed defrauded the state of New York out of tax payments.

Read the federal indictment in PDF

The U.S. Attorney’s Office in Manhattan said Cohen was expected to appear in federal court next week.

Cohen has developed a national reputation by representing the reprehensible: people facing terrorism charges. His most recent high-profile client is Suleiman Abu Ghaith, the son-in-law of bin Laden, who is charged with conspiring to kill Americans.

At the time that Cohen joined Ghaith's defense in May, he was already facing tax charges under a federal indictment handed down in June 2012.

Jerika Richardson, a spokesperson with the U.S. Attorney’s Office in Manhattan, told NBC News on Wednesday night that the new indictment was separate from the 2012 case and it was uncertain whether the two cases would be combined.

A call to Cohen’s Manhattan office went to his message service, and he didn't immediately return a request from NBC News for comment.

In an email to Reuters on Wednesday, Cohen said he was "fully confident that I will be vindicated and see today's 'new' counts as a continuation of a DOJ (U.S. Department of Justice) vendetta directed at me for my many years of challenging them at home and abroad."

On his website, Cohen calls the federal investigation of him “this witch hunt.” The website asks for contributions to a legal defense fund.

Cohen certainly has been a thorn in the government's side. Cohen represented Hamas political leader Moussa Mohammed Abu Marzook in attempting to prevent his extradition to Israel in a bombing case. The U.S. eventually freed Marzook, who went to Syria.

He also represented Patrice Lumumba Ford, who was accused of attempting to travel from Oregon to Afghanistan after 9/11 to fight against the U.S. The government attempted to prevent Cohen from representing Ford, who eventually accepted a plea deal.

Cohen’s website lists a series of other people accused of terrorism that he has represented.

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