A US Army probe blames a general and several other officials for contributing to an anthrax scandal that saw live samples of the deadly bacteria shipped across the United States and overseas, the Pentagon said Friday.

The investigation followed the May 2015 discovery that low levels of live anthrax spores had been discovered in an Army shipment supposed to only contain dead spores.

The samples originated from the Dugway Proving Ground research center in the Utah desert, and officials later determined live anthrax had, over a period of about a decade, been sent to 194 other research laboratories in all 50 US states as well as nine foreign countries.

A 150-page report into the issue found that, while the public was never put at risk and no single person was directly responsible for the unauthorized shipments, sloppy work practices and leadership shortcomings exacerbated the crisis.

"Leaders identified in the ... investigation report created conditions allowing a culture of complacency to flourish," the report states.

"As a result, laboratory personnel did not always follow rules, regulations, and procedures."

Personnel at Dugway identified in the investigation "routinely failed to take appropriate steps or actions that could have limited the inadvertent shipment" of anthrax samples, the report adds.

The investigation is especially critical of Brigadier General William King, who led Dugway as a colonel from 2009-2011.

"Colonel King was unwilling to take a deeper look at the operations he commanded, and ultimately perpetuated a complacent atmosphere," the report states, adding that he "repeatedly deflected blame and minimized the severity of incidents."

King told the USA Today newspaper that he couldn't comment on the matter, but said safety was of the "utmost importance."

Eleven other people are singled out in the report, but their names are redacted.

Major General Paul Ostrowski, who headed up the probe, told reporters a variety of factors including "gaps in science," institutional issues and personal accountability had contributed to the problem.

In explaining the science issues, Ostrowski said the Army needs to investigate the irradiation process used to inactivate anthrax spores, review safety protocols and conduct new research into testing procedures.

Officials have recommended that Dugway no longer produce material for external customers.