The Fairfax City man accused of masquerading as the nephew of filmmaker Steven Spielberg at a Catholic high school has been arrested for a third time, for allegedly possessing child pornography.

Police said yesterday that they found a piece of pornography depicting males under 18 years old when they seized dozens of videotapes, books, photos and documents in a search of Jonathan Taylor Spielberg's house last week. Spielberg was arrested Wednesday night on the misdemeanor pornography charge and released.

The search of Spielberg's house came after he was charged with forgery and making false claims in gaining admission to Paul VI High School, a Catholic secondary school in Fairfax City. Spielberg was arrested a second time last week and charged with forging a public document by lying about his age in his legal petition to change his name.

Spielberg said yesterday that he did not know what item led to the latest charge against him, and he declined further comment.

Contradictions continue to swirl about the case of Spielberg. He told police he is 27 years old, yet told school officials that he is a teenager, police said. A driver's license lists his age as 20.

How he allegedly hoodwinked Catholic school officials into allowing him to enroll, and what he did at the 1,300-student high school operated by the order of Oblates of St. Francis de Sales, remain a mystery.

Parents of students at Paul VI were baffled by the incident, in part because the school released no information until sending out a letter that most families received Saturday. The news yesterday of Spielberg's latest arrest only heightened their concerns.

"I'm still upset that they let him in," said Yvonne Johnson, mother of a Paul VI freshman. "It perturbs me because there's supposed to be a screening process. There's a lot of red flags that should've gone up, and I'm disappointed that Paul VI didn't catch them. I still feel like they're trying to put it under the carpet."

The Catholic Diocese of Arlington released a statement last night saying that it has no reason to believe that any current or former Paul VI students are "involved in any way with this most recent criminal charge."

Fairfax City police Detective Michael D. Boone said he is continuing to investigate Spielberg's activities with students and parents at Paul VI.

"I'm interested in any people that've had communication with Jonathan," Boone said.

Boone said his probe has been slowed because of a lack of cooperation from some students and parents. He also said he has been unable to interview the school's principal, the Rev. John Lyle, who first admitted Spielberg to Paul VI in the fall of 1998 as a part-time student.

"We're attempting to locate Father Lyle," Boone said, "in hopes of interviewing him."

Lyle has not returned repeated phone calls from The Washington Post.

A lawyer for Lyle's religious order said yesterday that his client is not avoiding the police and has placed at least "two return calls" to police this week.

Lyle "was told the detective did not come into work until 6 p.m.," said lawyer Vincent J. Morrison.

Morrison said Lyle was in New Jersey last week and is in Wilmington, Del., this week attending to church business.

Some students and parents have said that Spielberg received special treatment from the school, such as parking in the principal's parking spot and attending class sporadically.

Morrison said that was untrue and that Spielberg had been told not to park his BMW coupe in Lyle's spot.

Morrison said he had seen some of the documents Spielberg submitted to the school, which appeared "legitimate enough to fool an administrator who is trying to monitor 1,300 sets of paperwork. . . . I think Father Lyle and the administration were duped by a first-class, sophisticated con man."

Officials with the Catholic Diocese of Arlington said last week that a woman called the school in September 1998 and told them Spielberg wanted to attend Paul VI part time to prepare for a film role he would be playing as a high school student. Later, the school received a transcript from the "Beverly Hills Private School for Actors," which police said doesn't exist, and was admitted as a full-time student for the current school year.

Morrison said Spielberg was supposed to begin paying tuition this year, but never did, so the school sent letters requesting payment. In return, the school received a letter on DreamWorks SKG letterhead, the production company of Steven Spielberg. The letter said the Spielberg family was still paying a private tutor for Jonathan Spielberg, thus causing difficulty in also paying Paul VI, Morrison said.

CAPTION: Police say Jonathan Spielberg said he was related to filmmaker Steven.