The FBI has confirmed an investigation into the computer hacking of Sony Pictures Entertainment that saw several unreleased films of the studio leaking online and forced it to shut down its e-mail service.

A group called Guardians of Peace has claimed responsibility for hacking into the Sony computers a week ago but it is still not known whether they are responsible.

The hackers gained access to the studio’s system and arranged for a bizarre image and poorly worded text to appear on the computer screens of employees.

The FBI confirmed that they were investigating the hacking at Sony, said the Hollywood Reporter .

“The FBI is working with our interagency partners to investigate the recently reported cyber intrusion at Sony Pictures Entertainment,” the agency said in a statement on Monday.

“The targeting of public and private sector computer networks remains a significant threat, and the FBI will continue to identify, pursue and defeat individuals and groups who pose a threat in cyberspace.”

GOP threatened that the initial hacking was “just a beginning” and threatened to release more sensitive data claiming “We’ve obtained all your Internet data, including your secrets and top secrets. If you don’t obey us, we’ll release data shown below to the world.”

Unreleased films like Annie and To Write Love on Her Arms and Sony’s latest release, Brad Pitt-starrer Fury appeared at piracy Web sites over Thanksgiving weekend

Sony is investigating a possible link to North Korea as they believe the hack may have been a retaliation to their upcoming film The Interview starring James Franco and Seth Rogen. The comedy revolves around two CIA recruits who are assigned the task of assassinating North Korea dictator Kim Jong-un.