A suspect batch of anthrax may have been sent to the Pentagon after an Army laboratory in Utah mistakenly shipped out suspected live samples of the potentially lethal bacteria, a U.S. defense official said on Tuesday.

The suspected shipment, first reported by CNN, came from a batch that was meant to have been inactivated at the Dugway Proving Ground, but which tested live during the ongoing investigation, the official said.

The Pentagon said earlier on Tuesday that suspect anthrax samples had been sent to labs in 12 U.S. states, as well as Australia, South Korea and Canada, as far back as 2006.

One of the shipments was sent to Pentagon police, the officials told Reuters, but it was unclear whether the sample entered the Pentagon itself or a satellite facility.

The Pentagon did not immediately comment.

The U.S. military last week ordered a sweeping review of practices meant to inactivate the bacteria.

The Canadian government said on Tuesday it had received a shipment from the United States that might have contained live bacterium but that there were no reported illnesses. The Public Health Agency of Canada said it received the sample in August 2006 but that it had not been used for more than five years and was moved to a secure laboratory.

The Pentagon has advised all laboratories to stop working with any "inactive" samples sent from the Defense Department.