Poitras, who won an Academy Award for her documentary about Snowden earlier this year, claims that every time she entered the US for work between 2006 and 2012, she was detained and subject to extensive security screening over 50 times. The director and producer is now demanding the release of records documenting the period.

According to the lawsuit, Poitras' mobile phone, laptop, camera and notepads were also confiscated during the detentions, and authorities once threatened to handcuff her for trying to take notes while she was detained.

Law bypass

Poitras also claims that airport security agents said she had a criminal record - even though she doesn't - that her name was on a national security threat database, and, on one occasion, that she was on the US government’s No Fly List.

In a statement published by the digital rights group "Electronic Frontier Foundation," the Boston-born American said that she was filing the lawsuit against the Department of Homeland Security (DHS) and the Office of the Director of National Intelligence "because the government uses the US border to bypass the rule of law."

"This simply should not me tolerated," she added.

'Kafkaesque harassment'

"I am also filing this suit in support of the countless other less high-profile people who have also been subjected to years of Kafkaesque harassment at the borders. We have a right to know how this system works and why we are targeted," Poitras said.

The detentions are believed to have come to an end three years ago after journalist Glenn Greenwald published an article about the film maker's experiences and a group of documentary makers filed a petition to the DHS in protest to Poitra's treatment.

ksb/jil (dpa)