The controversy over Sony's film about North Korea has helped it generate record downloads. 

The studio says "The Interview" has been downloaded more than two million times, generating over $15 million (€12 million) in its first four days.

This ranks the film, with a fictional plot to kill North Korea's leader, as the most successful ever released by Sony Pictures.

Sony Pictures initially pulled the film, following a cyber attack against the company and threats against theatres that agreed to show the film.

The movie was shown at 320 cinemas in America on Christmas Day - less than 10% of the original number due to screen it.

It came as some cinemas in the US reported they were to tighten security for screenings.

On Christmas Eve, Sony announced their video-on-demand (VOD) plans for the film in US, with the film available digitally at the same time as its limited theatrical release.

In a statement, the company said the film would be available to rent or buy on Google Play, YouTube Movies, Microsoft’s Xbox Video and the dedicated websitehttp://www.seetheinterview.com. They are currently only available for US viewers.

The White House praised Sony for reversing its decision to pull The Interview, which features a fictional assassination of North Korea's leader.

The hackers also obtained and released sensitive internal emails involving senior executives at Sony Pictures.

Sony claimed it had had "no choice" but to cancel the release because cinema chains across the US had backed away from showing the film after the threats.