US government monitored North Korean hackers since 2010
The Interview is given as the reason for blaming North Korea Sony Pictures

The controversial dark comedy The Interview is tipped to cost Sony Pictures $200m in total after the film studio's systems were hacked and subsequently led to the company cancelling the release, as well as a class action lawsuit, expensive legal fees and software replacements.

According a Bloomberg report, while the movie cost $80m (£51m, €65m) to make and market, the spiralling costs from the fallout of the mass company hacking, could go above $100m.

"The cost to Sony from new software and hardware, employee labour to clean up the mess, investigation, lost productivity, and reputational damage, just to name a few, is at least over $100m and growing daily," Hemanshu Nigam, who founded the cybersecurity firm SSP Blue and has worked with Microsoft and News Corp, told Bloomberg.

The Interview stars Seth Rogen and James Franco as a television personality and his producer, who manage to net an interview with Kim Jong-un. They are then approached by the CIA, who instruct them to kill him.

Hackers had demanded the movie not be screened.

Sony Pictures was then hit by a vast cyber security breach which has led to unidentified hackers leaking unreleased movies, emails between senior executives, and confidential information relating to members of staff.

This includes social security numbers, salaries, healthcare records, performance evaluations and reasons for termination.

Furthermore, Sony Pictures is also being sued by two former employees for failing to protect key staff pay and conditions data from hackers.

The plaintiffs also claim addresses, phone numbers and birth dates were leaked.

The former employees filing the lawsuit are seeking compensation "for any damages as well as credit monitoring services, identity theft insurance and other assistance".

There was speculation that hackers backed by North Korea launched the attack, as the country was infuriated with the content of The Interview.

Bloomberg claims that a source close to the FBI probe said "US officials have concluded that North Korea is behind the cyber-attack and plan an announcement this week."

However, according to IBTimes UK's tech editor there is no confirmation or substantial evidence backing up this theory.