A film based on the memoir a pro-democracy activist who was brutally tortured in the 1980s by South Korea's military rulers is provoking discussion about the country's not-so-distant authoritative past and its influence on the presidential election.

"National Security" premieres Saturday at the Busan International Film Festival. It tells the story of Kim Geun-tae, who endured 22 days of torture in a notorious Seoul interrogation room because of alleged links to North Korea and a plot to overthrow South Korea's military regime.

The film is due for nationwide release in November, just a month before the election. One of the candidates, Park Geun-hye, is the daughter of dictator Park Chung-hee, who ruled the country for 18 years until his assassination.