Story highlights Science experts say there was no risk to the public.

The anthrax shipments went to 11 states and South Korea.

Washington (CNN) In what is emerging as a widening military investigation into the accidental shipment of live anthrax, the Army discovered it may have shipped the live pathogen to Australia back around 2008 or 2009, the Pentagon said Friday.

Following the discovery that 22 shipments of live anthrax had been sent over the past year to private labs and a U.S. military facility in South Korea, a lab in Dugway, Utah, where the samples originated, went back and checked further into its inventory, according to a Defense Department official.

It discovered a still-live batch of anthrax from 2008. Records showed some had been shipped to Australia, but the official could not immediately verify if the shipment had been made in 2008 or 2009, or whether the spores in the shipment to Australia were found to be live. The official said the Australians were notified.

No other details were immediately available Friday. The Pentagon is now reviewing the anthrax inventory to see if there are other live samples. It is also reviewing the irradiation protocol it uses to determine if it's faulty. But even after irradiation to kill the spores, there are two subsequent verification tests undertaken to make certain the material is dead, so it is not clear where the failure occurred and if there are other live anthrax samples the Pentagon is not aware of.

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Friday's development comes after the revelation that four lab workers in the United States and up to 22 overseas were put in post-exposure treatment after the U.S. military inadvertently shipped the live samples -- some via FedEx -- to 24 laboratories in 11 states and the two countries.

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