Maria Butina, the Russian operative who used her activism with the National Rifle Association to illegally infiltrate U.S. conservative political circles, was released from federal prison and deported Friday after serving most of an 18-month sentence, officials said.

A spokesperson for the Federal Correctional Institution in Tallahassee, Florida, said Butina left the facility earlier in the morning and was taken into custody by immigration authorities.

U.S. Immigration and Customs Enforcement said in a statement that Butina left the U.S. on a direct flight from Miami International Airport to Moscow that departed at around 6 p.m.

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In July 2018, the gun-loving former aide to a top Russian official was arrested and charged with infiltrating politically powerful U.S. organizations to push Moscow's agenda.

In December 2018, she pleaded guilty to one count of conspiracy to violate the law governing foreign agents operating in the U.S.

She was sentenced in April of this year, although the judge gave her credit for nine months she had already served.

She remains the only Russian national to be arrested in connection with the U.S. government's investigation into Russian interference in the 2016 election.

Speaking to National Public Radio in May, Butina denied that she was part of a conspiracy or "grand plan."

"I should have registered [as a foreign agent], which I didn't. And this is why the whole this thing got started," she said.

"But that wouldn't be appropriate to say that this was all one grand giant plan, and I'm a part of some grand giant plan. There is no proof of that."

Originally from a remote town in Siberia and a graduate of American University, Butina learned to assemble and dissemble Kalashnikovs as part of a school first-aid class, her family revealed in an interview with NBC News in January.

Maria Butina featured in the Right to Bear Arms magazine in September 2014. Courtesy of Butina family

She founded a gun rights group called Right to Bear Arms and appeared as a model in its magazine.

Butina's arrest and imprisonment became an international flashpoint after Russian President Vladimir Putin said her sentence represented "lawlessness."

"In order to not make it look completely ridiculous, they gave her 18 months to show that she's guilty of something," he said in April.