In a case comparable to the botched “Fast and Furious” gun-running investigation, ATF agents and federal prosecutors in Arizona endangered public safety by allowing a suspect to smuggle grenade parts into Mexico for possible use by drug cartels, the U.S. Department of Justice’s inspector general reported Thursday.

The report said the Office of the Inspector General first learned of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) grenade parts sting during its investigation of Operation “Fast and Furious,” in which agents purposely allowed licensed firearms dealers to sell weapons to illegal straw buyers, hoping to track the guns to Mexican drug cartel leaders and arrest them.

It noted that the two cases involved the use of similar strategy and tactics in allowing dangerous weapons to fall into the hands of deadly Mexican drug gangs.

In the grenade case, the report said that ATF agents learned in October 2009 that American Jean Baptiste Kingery was ordering large amounts of grenade components from an online military surplus dealer and suspected that he intended to smuggle them into Mexico to be converted into live grenades and sold to Mexican drug cartels.

Grenade fuse assemblies intercepted by ATF in January 2010. ATF

Rather than arresting Kingery when he tried to bring the parts into Mexico, ATF agents instead intercepted two shipments and marked them so they could be identified later, then allowed them to be delivered, the report said.

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But while they were conducting surveillance to see if Kingery was smuggling the parts into Mexico in violation of the U.S. Arms Export Control Act, agents lost track of the suspect. They later discovered he had traveled to Mexico during the period when he was unwatched. Months later, the IG report says, the ATF discovered that "two live grenades recovered at a crime scene in Mexico contained component parts that bore markings of the type ATF used on the components delivered to Kingery."

Mexican police have claimed that some of those components were used to assemble live grenades that were used by drug dealers to attack police there.

The report also criticized officials in the U.S. Attorney’s Office for the District of Arizona for declining to prosecute Kingery after he was arrested by in June 2010 by U.S. Customs and Border Patrol agents as he tried to smuggle ammunition and grenade parts into Mexico.

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“This failure to act reflected inadequate consideration by the agents and prosecutors of the risk to public safety in the United States and Mexico created by Kingery’s illegal activities,” the report concluded.

After U.S. prosecutors declined to charge him, Kingery was later arrested in Mexico, where he has been charged with violating organized crime laws.

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The ATF has been under close scrutiny since the “Fast and Furious” operation, which ran from 2006 to 2011, became public.

Guns marked by ATF agents were later determined to have been used in the fatal shooting of U.S. Border Patrol Agent Brian Terry in December 2010 and Mexican authorities said they also had turned up at crime scenes in which at least 150 Mexican civilians were killed or injured.