The FBI is offering a $200,000 reward for information leading to the arrest of former U.S. Air Force special agent and counterintelligence specialist Monica Witt, who was charged in 2019 with espionage in connection with accusations she shared highly classified U.S. intelligence with Iran.

The FBI said in a statement Thursday that it's still trying to locate Witt, who they say defected to Iran in 2013.

"The FBI has not forgotten and believes that during this critical moment in Iran's history, there is someone who knows something about her whereabouts," said Daniel Wierzbicki, special agent in charge of the FBI Washington Field Office's Counterintelligence and Cyber Division. "The FBI wants to hear from you so you can help us apprehend Witt and bring her to justice."

In February 2019, prosecutors alleged that Witt shared information about a classified Defense Department program with the Iranian government and assisted Tehran's intelligence services in targeting her former colleagues in the U.S. government. Authorities said Witt worked with Iran's Islamic Revolutionary Guard Corps, the elite military force tasked with expanding Tehran's influence globally.

Witt entered the Air Force in 1997 and left in 2008, according to the Justice Department. She was also a Defense Department contractor until 2010. 

Prosecutors said Witt traveled to Iran in 2012 to attend a conference that criticized "American moral standards" and promoted anti-U.S. propaganda. She returned the following year and was given housing and computer equipment by Iranian officials. Authorities allege she later began working on behalf of Tehran by sharing classified information and gathering intelligence on former U.S. intelligence colleagues.

The same 2019 indictment charged four Iranians for conspiracy and aggravated identity theft, accusing them of helping Witt gather information on her former U.S. government colleagues.