Relatives of Sept. 11 (search) victims are upset that authorities didn't act more forcefully when a man told the FBI in 2000 that he'd been trained as a hijacker for Usama bin Laden (search).

In April 2000, the man, a British Muslim, went to the FBI's Newark, N.J., office and told agents of plans to hijack U.S. airliners, according to the report of a Senate-House committee that studied the attacks. After his claims were investigated, he was turned over to British authorities and eventually freed.

Victims' families, responding Thursday to new details of the case or in some instances hearing about it for the first time, said the episode was another example of lapses by authorities who might have foiled the Sept. 11, 2001, plot if they had been more vigilant.

"Another brand of negligence," said Patty Casazza of Colts Neck, N.J., whose husband, John, died in the World Trade Center. "How many warnings do you have to have until news of a hijacking is to be deemed credible?"

Casazza first heard of the report Thursday and said, "It is another piece of foreknowledge of the attack that was put aside."

Kristen Breitweiser of Monmouth, N.J., whose husband, Ronald, also died in the World Trade Center (search), had previously heard about a source informing authorities of a hijacking plot.

"How many instances will our intelligence communities need prior to an attack for them to properly investigate?" she asked. "This is another example of them having a piece of the puzzle of the 9-11 plot available to the intelligence community that was not capitalized on."

The man was identified Thursday as Niaz Khan (search), a Briton of Pakistani descent, by The Wall Street Journal and "NBC Nightly News," both of which interviewed him.

The committee's December 2002 report said the "walk in" told the FBI that he had learned hijacking techniques and received arms training in a Pakistani camp and that he was to meet five or six people in the United States.

"Some of these persons would be pilots who had been instructed to take over a plane, fly to Afghanistan, or, if they could not make it there, blow the plane up," the report stated.

Although Khan passed polygraph testing, the bureau was unable to verify any aspect of his story or identify his contacts in the United States, the report said.

Khan, 30, said in the media interviews that Islamic radicals lured him into their group in London with the promise of paying his gambling debts.

"First they say, 'I can help you,"' he told NBC in broken English. He said two men invited him into a car and began by asking if he'd heard of bin Laden.

He said he was taught hijacking basics along with about 30 others in Pakistan, learning how to smuggle weapons through airport security and techniques to overpower passengers and crew.

He said he flew into New York to meet a contact but got cold feet, gambled away the money his handlers had given him and, in fear, turned himself in and confessed.

The FBI investigated Khan's story for several weeks but could not verify his allegations.

FBI officials in Washington and Newark declined to comment Thursday.

Lawyers for the Sept. 11 victims encouraged Khan to speak publicly about his claims, The Wall Street Journal and NBC reported.

Philip Zelikow, executive director of the 9-11 commission, said the panel is reviewing Khan's claims, which will be addressed in part in the commission's final report next month. He declined to comment on Khan's credibility.

"We've been aware of this for some time," he said. "I don't want to get into specifics, but we are always interested in 9-11 information."