Two vials of a deadly bacteria may be missing from a government lab in Trenton - or officials might simply have miscounted, they said yesterday.

Over the last three weeks, officials have been readying samples from the Trenton Distribution Center - a postal facility in Hamilton where anthrax-laced letters were discovered in 2001 - for a move to a new, safer bioterrorism facility.

An inventory turned up 350 two-inch test tubes of liquid-encased anthrax spores, when 352 should have been on site at the New Jersey Public Health Environmental Laboratory where the anthrax has been stored since its removal from the postal facility.

"We think that at the end of the day, it's going to be basically a transcription error, or there wasn't an exact logging to what came in," said Eddy Bresnitz, New Jersey deputy commissioner of health and senior services. "We don't think it's going to turn out to be missing inventory."

Bresnitz and Fred Jacobs, the head of the state health department, believe that a discrepancy is likely because a more thorough count was performed in advance of the move to the new lab a short distance away.

Bresnitz said he could not explain why a more exhaustive count was not performed earlier.

For now, the state has notified the Centers for Disease Control and Prevention, the FBI, and the public of the potentially missing vials.

"We don't think there's any threat to the public's health," Bresnitz said. "The way we have it stored, it can't be used in its current form as a weapon of mass destruction."

In order for the samples to be weaponized, a person would have to have highly specialized knowledge and equipment and take several steps, he said.

Officials said that 11 people had access to the samples, all of whom had photo ID, access cards and a padlock key. The 11 - research scientists and microbiologists - also had FBI background checks and were interviewed after the discrepancy was discovered.

The lab has a 24-hour security guard and is monitored by video cameras, as well.

Another count is under way, and state officials expect to release a report analyzing what happened to the anthrax on Wednesday.

Four letters containing anthrax were mailed through the Hamilton postal facility in September and October of 2001. Four workers at the regional processing center and one postal carrier were sickened, though all recovered.

Five people died nationwide.

Letters were sent to NBC News, the New York Post, U.S. Sens. Tom Daschle (D., S.D.) and Patrick Leahy (D., Vt.), contaminating the Hart Senate Office Building.

No arrests have been made.

Fumigating and restoring the Hamilton facility cost an estimated $100 million and took more than three years.

Contact staff writer Kristen Graham at 856-779-3927 or kgraham@phillynews.com.