The armored Packard that protected Joseph Stalin is causing an international stir as Bulgarian officials claim the vehicle, which now resides in an Illinois museum, was stolen in 1992, ABC7 reported.

Wayne Lensing, who works in historic auto attractions at a Roscoe, Ill., museum, purchased the 1937 black Packard Super 12 on eBay and closed the deal. The 15,000-pound, steel-armored car featuring bulletproof glass three inches thick stayed at the museum next to other world leader limousines until federal agents knocked on Lensing's door in 2011.

"Show me a badge and say we're here to confiscate this car ... and I'm in total shock because I worked real hard to be able to save up to buy the car," Lensing said.

United States prosecutors put in motion a federal civil suit to return Stalin's car to the Bulgarian government.

Officials claim the car was stolen in 1992 from outside a museum in Sofia, the Bulgarian capital. Ivan Kristov, a Bulgarian national who has been named the man who first brought the Stalin car to the U.S., says a friend sent him the car to sell in Chicago.

Stoil Slavov, the friend and business partner, was killed by his fellow members of the Russian mob, according to Kristov. Connected with a car insurance racket, Slavov was blown up in an attack soon after the sale of the Stalin car.

"The mobsters that stole it, they got assassinated! So I mean, I'm totally in awe, I'm over here with this car, my God, am I next?" said Lensing, who said he purchased the car from another private collector with no idea that it was stolen.

Kristov also denies knowing the car was a theft.

"What's stolen? Stolen, I don't know, for me it's not stolen," he told ABC7.

Court papers claim the car is worth millions. Claiming the car belongs to Bulgaria, officials say the vehicle was given as a gift to the country's prime minister as part of a 1970 treaty.

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