WASHINGTON – The top official in charge of analyzing terror threats did not cut short his ski vacation after the underwear bomber nearly blew up an airliner on Christmas Day, the Daily News has learned.

Michael Leiter, director of the National Counterterrorism Center since 2007, decided not to return to his agency’s “bat cave” nerve center in McLean, Va., until several days after Christmas, two U.S. officials said.

“People have been grumbling that he didn’t let a little terrorism interrupt his vacation,” said one of the sources.

The NCTC, the post-9/11 clearinghouse for intelligence to detect terror plots against the U.S., is under intense scrutiny for failing to “connect the dots” on Nigerian bomber Umar Farouk Abdulmutallab.

Leiter’s spokesman declined to say when the terror-center chief returned to Washington and fully retook the helm of his analysis agency, which is near CIA headquarters just outside the nation’s capital.

“It is our policy to not make our director’s schedule available to the public,” center spokesman Carl Kropf said in an e-mail.

Leiter has long been well-regarded, and he was not the only official in the homeland security orbit to skip town for vacation during the holidays. President Obama himself stayed in Hawaii until Jan. 4.

But Leiter’s decision to stay close to the ski slopes instead of his headquarters – ground zero for defending the nation against terror – has raised eyebrows among intelligence officials, who have been scrambling since Dec. 25 to figure out what went wrong and plug the holes.

Leiter – appointed by President George W. Bush – already ranked high in the buzz over whose heads could eventually end up on Obama’s chopping block.

Without mentioning Leiter or the NCTC by name, Obama made it plain in a Tuesday speech that there was intelligence in the center’s hands that should have been “fully analyzed and fully leveraged” to stop Abdulmutallab from boarding Northwest Flight 253.

Abdulmutallab, badly burned by his device after it failed to fully detonate, was indicted Wednesday on six counts of terrorism and is expected in federal court in Detroit tomorrow for his arraignment.

Obama also dropped the bombshell Tuesday that U.S. spooks knew the previously locally focused Al Qaeda branch in Yemen aspired to attack the U.S. homeland. The intelligence community “failed to connect those dots,” he said.

“The information was there,” Obama said. “Agencies and analysts who needed it had access to it.”

Officials throughout the government recognized the terror center was the target of Obama’s wrath, since it was the agency set up on the recommendation of the 9/11 Commission in 2004 to analyze terror-threat intelligence.

An affable ex-Navy pilot, Leiter – like Obama – was editor of the Harvard Law Review. He clerked for liberal Supreme Court Associate Justice Stephen Breyer and was a career Justice Department prosecutor before Bush appointed him NCTC director.

But Leiter has been indiscreet too. He once blabbed in a bar that Washington Mayor Adrian Fenty was “the dumbest public official I’ve ever met.”

On Jan. 2, Leiter surprised many Obama administration officials with his first statement on the Detroit bombing attempt – eight days after it happened.

Leiter said the plot was typical of “insidious terrorist threats we face,” and said Al Qaeda continues “to refine their methods to test our defenses and pursue an attack on the homeland.”

That same day, National Public Radio had aired an interview – taped before Christmas – in which Leiter said it is “harder and harder for us to detect” Al Qaeda’s improved capabilities.

“We’re not going to stop every attack,” he predicted, ominously. “Americans have to very much understand that it is impossible to stop every terrorist event. But we have to do our best.”

Meanwhile, a newspaper reported that border security agents were waiting to grill Abdulmutallab when he landed in Detroit after they learned of his extremist links.

If the intelligence had been discovered sooner, border agents said it could have led to questioning and search a of Abdulmutallab before he boarded the Amsterdam-to-Detroit flight with a one-way ticket.

“The people in Detroit were prepared to look at him in secondary inspection,” a senior law enforcement official who requested anonymity told the Los Angeles Times.

Homeland Security Secretary Janet Napolitano was bashed for saying 48 hours after the near-miss attack that “the system worked,” but her predecessor said she’s doing a heckuva job.

“Although that initial statement was obviously a misstep, I think she has recovered from that. I think she has actually done a good job,” ex-Secretary Michael Chertoff told “Fox & Friends” Wednesday.