NEW YORK (CNN) - The acting Food and Drug Administration (FDA) commissioner on Monday disputed a published report that said agency officials knew before Oct. 5 that British health authorities might suspend the operating license of Chiron's vaccine plant in Liverpool.

"Neither of our most recent inspections gave any indication that Chiron would not be able to fulfill their recent public promise to deliver between 46 and 48 million Fluvirin doses to the U.S. market beginning in early October," Dr. Lester Crawford told reporters in a conference call.

The Washington Post reported over the weekend that British health officials said their U.S. counterparts were told last month that problems at the vaccine plant in England could affect supplies to the United States.

The newspaper said records from Britain's Department of Health show that Chiron "warned officials of the U.S. Food and Drug Administration and the British Medicines and Healthcare Products Regulatory Agency on Sept. 13 that potential contamination problems remained unresolved at the plant," the story said.

That account differs from those of U.S. health officials, who said the decision by Britain's health authorities to suspend production for three months because of contamination concerns at the plant surprised them.

"It was our expectation, based on our communication with Chiron (CHIR: Research, Estimates), that the production would be cleared up," Crawford said. "It was in a minority of lots."

He said the British authorities had not contacted the FDA about the issue between that date and the announcement of the suspension.

Asked whether he would have changed the way the matter was handled, Crawford said "standard procedures" had been followed, and he would change nothing.

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Crawford said an inspection of the plant in June 2003 had identified higher-than-expected levels of bacteria in a "limited number of early-stage production" of vaccine that had been grown in eggs the previous year.

But the final product was not contaminated, because filtering processes removed it, he added.

Contamination that was identified Aug. 25 was found in later stages of vaccine production, he said.

Chiron identified the problem in eight of an expected 92 lots, he said. No one at the FDA's center for biological evaluation and research was notified by Chiron "of any increased level of concern," he said.

The plant had been on track to produce about 48 million doses of vaccine, about half the U.S. supply.

A team of FDA scientists flew to the Liverpool plant within hours of the announcement that production at the plant was suspended, and U.S. orders would not be filled. The team is investigating to see whether any of the vaccine can be salvaged. Their report should be complete this week, he said.

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Some 6 million doses had already been sent to the United States before the announcement, but they remain "on hold," he said.

"A determination will be made about their fate as soon as we get this report finalized from England."

The scarcity of flu vaccine underscores the fragile nature of the U.S. flu vaccine supply, in which just two major companies -- both of which use an egg-based product that requires several weeks to produce and a number of complicated steps to purify -- supply the U.S. market.

"We believe that there may be means to develop this kind of vaccine without use of egg-based product," Crawford said. "We believe there needs to be some research into that."