The second-highest grossing ROK film this year is another star-studded spy thriller, The Berlin File, seen by 7.1 million people.

ROK citizens are still urged to report spies for hefty cash rewards, although not as strongly as in the past when children were taught at school how to recognize spies by their behavior or accent.

The last remaining legacy of the Cold War has inspired hordes of DPRK-themed films in the ROK for decades.

One high-profile case saw a group of 30 elite Pyongyang commandos gunned down in downtown Seoul in 1968 after they secretly crossed the border with a mission to kill then-ROK president Park Chung-hee.

Cross-border reconciliation in the late 1990s under the engagement policy of the late ROK ex-presidents Kim Dae-jung and Roh Moo-hyun encouraged filmmakers to put a human face on people from the DPRK.

Director Jang said that top young actors are now vying for DPRK spy roles, as opposed to fearing the impact such parts might have on their image.

Since 2010, five high-profile spy films have been released and three more are in production, including Red Family by acclaimed director Kim Ki-duk.

The popularity of such spy films marks a sea change from the past, when casting DPRK characters in any positive light was a grave offence against state censors and the notorious ROK National Security Law.

Late legendary director Lee Man-hee was arrested and charged in 1965 with portraying DPRK soldiers as "humane and merciful human beings" in a film he was making.

Agence France-Presse