More than 1,000 North Koreans have been jailed for secretly watching South Korean TV shows and films as the communist regime battles an inflow of foreign culture, a Seoul-based defector group said Monday. North Korea Intellectuals Solidarity said some 1,200 people are in jail in the northwestern city of Kaechon for the offence. It cited a source in the prison, which has a total of 3,000 inmates. Access to foreign pop culture is strictly banned for ordinary people in the isolated nation, with violators facing hefty fines or jail terms. But a growing stream of pirated DVDs and music CDs smuggled from China, the North's neighbour and major trade partner, has made the capitalist South's pop culture increasingly popular, the group said on its website. "The prison official said it was the first time the number of people jailed solely for watching the South's TV dramas has gone over 1,000... now the prison is overcrowded with such prisoners," the group said. The group, citing another source in the North, said Pyongyang created a special police unit in January to crack down on those with "rotten spirit". Those who are caught are usually jailed for between two and five years and face harsher treatment in prison than other offenders, it said. News reports and North Korean defectors have said even the reclusive and tightly controlled North could not escape Hallyu -- the Korean Wave -- a reference to the surging popularity of South Korean pop culture in Asia. Pyongyang launched a crackdown on women emulating the looks and hairstyles of popular South Korean actresses, calling it "the South's delinquent look," the Seoul-based Daily NK online newspaper reported last month.