By JAMES GORDON MEEK in Washington
and TRACY CONNOR in New York

In a bizarre coincidence, Nick Berg crossed paths with Al Qaeda years before its henchmen beheaded him, when his E-mail and password wound up in the hands of 9/11 suspect Zacarias Moussaoui.
It happened in 1999, when Berg was at the University of Oklahoma and Moussaoui was enrolled at a nearby flight school, allegedly training to be an Al Qaeda hijacker.

After Moussaoui came under scrutiny in the Sept. 11, 2001, terror attacks, the FBI discovered he had Berg's university E-mail password.

"In 2002, the FBI was following millions of leads in the wake of 9/11, and one led to Mr. Berg," said a senior Justice Department official.

After questioning Berg about the tie, the feds concluded he had never actually met Moussaoui, who had friends and roommates at the same college.

The matter remained closed until Berg's ill-fated visit to Iraq this year.

When he was detained by authorities in Mosul in March, FBI agents came to grill Berg, and he volunteered details about his previous dealings with the bureau, the official said.

But the eerie link between Berg and the terrorist cabal that later decapitated him "turned out to be total coincidence," the official said.

U.S. intelligence officials have confirmed their suspicions that it is Al Qaeda associate Abu Musab al-Zarqawi who is seen killing Berg on the shocking videotape.

Using voice analysis, they determined that Zarqawi - a one-legged mystery man with a $10 million bounty on his head - was the hooded figure who wielded the knife.

Berg's family, however, is also blaming the White House for his gruesome death.

"Nicholas Berg died for the sins of [President] George Bush and [Defense Secretary] Donald Rumsfeld," his father, Michael, told reporters. "This administration did this."

The family produced an E-mail yesterday that appeared to confirm Nick Berg was in U.S. custody when he fatefully missed his plane out of Iraq in March - even though officials insist he was held by Iraqis.

"I have confirmed that your son, Nick, is being detained by the U.S. military in Mosul. He is safe," Beth Payne, the U.S. consular officer in Iraq, wrote to the family April 1.

The State Department told the Daily News Payne was misinformed, but didn't learn until April 7, a day after Berg was freed, that he'd been in Iraqi custody.

A police chief in Mosul, however, said Berg was never arrested by Iraqi authorities and Berg's own E-mails home said U.S. soldiers had been guarding him.

Berg, 26, had traveled to Iraq to drum up work for his radio-tower business and planned to fly home to West Chester, Pa., March 30 for a pal's wedding.

Because he was detained in Mosul, he missed his flight and was still trying to make his way home - through Turkey, according to one friend - when he vanished April 9.

U.S. officials have said they told Berg he should leave Iraq when he was released and offered him a flight back to safety.

But Michael Berg, an anti-war activist, said his son feared he might be killed on the treacherous route to the airport and decided to make his own way.

Michael Berg also took a call yesterday from presumptive Democratic presidential nominee John Kerry.

"He feels let down by, let down by those who should have been protecting his son," Kerry told Fox News' Alan Colmes.

A memorial is set for Nick Berg today, and high school friends have set up a Web site in his honor.

With Derek Rose in West Chester, Pa.