Since its release on Nov. 23, Frozen 2 has earned $61.2 million in Korea. The sizeable haul makes Korea the film's third largest market worldwide, trailing only North America ($287.6 million) and China ($90.5 million) — an impressive feat for a country of just 51 million people.

On Sunday, the Public Welfare Committee (PWC), an NGO based in Seoul, filed a complaint with South Korea's Central District Prosecutors Office, requesting a probe into Walt Disney Korea's suspected monopoly of the domestic movie market.

The organization alleged that Frozen 2 occupied more than 88 percent of Korean screens on its opening day of Nov. 23, which violates the country’s anti-monopoly law. The PWC contends that Disney's wide release of the film falls under a clause that defines any individual or company with over 50 percent of market share as a "market-dominant enterprise." Disney has "attempted to monopolize the screens and seek great profit in the short term, restricting the consumer's right to choose," PWC's complaint said.

Current Korean law pertaining specifically to movie exhibition states no cap on the share of screens that one film can occupy, but the recent dominance of imported Disney tentpoles and local blockbusters by the major Korean studios has sparked fervent industry debate over the issue.

Upon taking office in April, Korea's incoming Culture Minister Park Yang-woo promised to consider implementing a screen quota system for the domestic movie industry. That same month National Assembly Representative Woo Sang-ho of the ruling Democratic Party of Korea floated a bill that states the percentage of any film being shown at any multiplex theater cannot surpass 50 percent during prime moviegoing hours, defined as between 1 p.m. and 11 p.m. The bill is currently pending in the National Assembly.

Korea's large multiplex owners are opposed to the bill, but the country's indie film community, as well as many professionals working within commercial industry, have rallied in support of a new screen quota.

Last Monday, a group of filmmakers calling themselves the "Cineastes Council for Anti-Monopoly" issued a statement urging the government to address the issue aggressively. "The screen monopoly is not a one-off case," the group said. "The government has to tackle the winner-take-all cinema market."

Frozen 2 is on track to surpass the huge success of Disney's first Frozen feature from 2014. That film earned $76.6 million, the most ever for an animated film in South Korea.

Despite allegations of a monopoly, there has been confusion within the Korean film industry over the methodology and measures used to calculate screen shares.

The metric used by PWC, as well as other film industry bodies, to measure screen share uses the percentage of screens showing a specific film at least once in the given day. But the other organizations, including the state-run Korean Film Council (KOFIC), calculate screen share by taking the total number of times a certain film was shown, and dividing it by the total number of times any film was shown on that day.

Using KOFIC's measure, the screen share — or percentage of showings — of Frozen 2 on Nov. 23 was 46.3 percent, not the 88 percent figure cited by PWC.