ALBANY — A federal case against a former stay-at-home father from Niskayuna, who allegedly made pornographic movies with teenagers, is being challenged after the FBI seized computer files from the man’s home that contained private attorney-client information.

The challenge stems from an FBI raid last December at the central New York home where the suspect, Abraham Pearson, 49, has been living with his father, an attorney who has been assisting him in his defense. FBI agents viewed privileged materials that contained portions of Pearson’s defense strategy, according to Pearson’s attorneys.

“It’s an obvious overstep of their authority to execute a search warrant on a client’s house, when we were literally at that time weeks away from trial,” said Kent B. Sprotbery, Pearson’s defense attorney in Albany. “Based upon that, I think the whole indictment’s in jeopardy.”

Federal authorities have recused the assistant U.S. attorney who’d been handling the case and replaced him with another prosecutor from Washington, D.C.

At issue are several computer files, including some that are encrypted, that the FBI seized from the home of Pearson’s father, Elijah. Federal authorities raided the home after a man from Ohio, who is a government witness in the case, told FBI agents that he returned copies of illicit movies to Pearson that Pearson had produced in his Niskayuna home, records show.

The FBI’s search didn’t turn up any pornography, but authorities allegedly were able to view Pearson’s own notes about his legal strategy.

“They peeked behind the curtain to figure out which way we’re going in (our defense),” Sprotbery said.

A second legal struggle in the case is unfolding over the encrypted files seized by the FBI during the same raid. The contents of those files have not been publicly disclosed.

The FBI and the Justice Department have asked a judge to order Pearson to disclose a password needed to access the secret files, which they said may contain child pornography. However, a law enforcement official close to the case said the FBI already has accessed the files but the agency is reluctant to testify about the methods it uses to crack encrypted files.

“This is not a case that’s worth compromising national security,” the law enforcement official said.

U.S. District Judge Thomas J. McAvoy is expected to decide the legal arguments in the coming weeks. The trial is scheduled to begin June 5.

Pearson’s case broke in November 2003 when his upscale Orchard Park Drive home was raided by the Niskayuna Police Department, acting on a tip from a teenager. Authorities said they found a makeshift movie studio in Pearson’s basement where he allegedly made pornographic films that starred himself, two teenage girls and at least one teenage boy.

Pearson’s wife, a physician, filed for divorce as a result of his arrest and authorities said she had no idea what allegedly had been unfolding in the home. They have three children but authorities said there are no allegations they had been abused.

Pearson, who faces a mandatory minimum of 10 years in prison on the federal indictment, was arrested on state charges in June 2003. The charges, including rape, sodomy and using a child for a sexual performance, were dropped in favor of a federal indictment after Pearson rejected a plea offer from Schenectady County prosecutors. He has also rejected plea offers from federal prosecutors and faces more than 30 years in prison if convicted at trial.

Pearson remains free on $100,000 cash bond.