Damascus (Web Desk): A Federal Bureau of Investigation (FBI) employee, who was assigned to investigate a German member of the Daesh terror group, traveled to Syria in 2014 and married the key operative, according to a report.

Daniela Greene, who worked as a translator for the FBI, managed to hide her real whereabouts from the bureau and warned her rapper-turned-terrorist husband Denis Cuspert about the investigation, CNN reported.

Greene travelled to Turkey in June 2014 and entered Syria through Gaziantep, a city located near the Syrian border.

Cuspert, also known as Deso Dogg, has been featured in many propaganda videos. Praising former al-Qaeda leader Osama bin Laden in a song, threatening former President Barack Obama with a throat-cutting gesture, and holding a freshly severed human head are some of the things he has done before Daesh’s camera.

The FBI put Cuspert on the radar after it found out about his growing influence as an online recruiter, going by the name of Abu Talha al-Almani.

According to the report, Greene “seemed to realise she had made a terrible mistake” weeks after marrying Cuspert. She returned to the US soon after.

Greene, 38, was arrested upon arrival and charged with making false statements involving international terrorism. She pleaded guilty and received only two years in prison before being released last summer.

Prosecutors had described Greene’s actions as “egregious,” deserving of “severe punishment.”

The FBI admitted to CNN in a statement that it had to take “several steps in a variety of areas to identify and reduce security vulnerabilities” as a result of the case.

Former State Department spokesman John Kirby said Greene’s conduct amounted to “a stunning embarrassment” for the bureau.

Assistant US Attorney Thomas Gillice said Greene had “violated the public trust” and “endangered our nation's security.” However, he said the rogue agent had been handed a lighter sentence because of her cooperation.