A FBI translator with a top-secret security clearance travelled to Syria where she married a key ISIS operative she had been assigned to investigate.
Daniela Greene lied to her bosses about her movements before warning her new husband he was under investigation, according to US federal court records.
Her husband was Germany-born Denis Cuspert, who rapped under the name Deso Dogg and was known as Abu Talha al-Almani in the terror group.,Daily Mirror reports.
American considered the jihadist one of the most violent operatives in Syria.
He was also found to have sung song songs in praise of Osama bin Laden , threatening Barack Obama with a throat cutting gesture, and holding a bloody head in a recruiting video.
When she was approached about her marriage, she said “If I talk to you my family will be in danger.’
Within weeks of their wedding, Green, who was born in Czechoslovakia and raised in Germany, realised her marriage was a mistake and fled back to the US, where she was arrested and eventually served two years in prison.
The 38-year-old, who was released from prison last summer, pleaded guilty to making false statements about terrorism and agreed to help US authorities.