Narrated by Christian Slater, the film was directed and produced by Dan Gordon, and co-produced by Nick Bonner - the latter two documentarians have focused on the isolationist North with other projects such as The Game of Their Lives and State of Mind.
The film screened in Pusan and Sundance before Berlin.
Paul Yi, whose E Pictures has gone independent after parting with MK Pictures, is handling sales. He brokered the deal with Gary Palmucci and Don Krim at Kino, and Paul Wiegard at Madman.
Yi is also producing a dramatized feature version of Crossing the Line, with Academy and BAFTA awards-nominated screenwriter David Franzoni (Gladiator) writing the script.
'It will be a Hollywood-scale picture with an Asian-scale budget,' says Yi.
Franzoni is also writing and directing the remake of the 2000 Korean hit Joint Security Area (JSA).
Crossing the Line was sold at the last Asian Film Market to Pretty Pictures for France, Dongsoong Art Center for Korea, and Cinequanon for Japan.