HBO said Monday its network was victimised by a cyberattack, with the hack apparently resulting in the leak of a script of the popular series Games of Thrones and content from other productions.

A statement by the Time Warner-owned TV group said a “cyber incident” resulted in “the compromise of proprietary information,” and that the company had contacted law enforcement and outside cybersecurity firms.

The statement did not indicate what was compromised, but several media reports said hackers obtained the script of a new episode of the award-winning fantasy series as well as unaired episodes of two other programs, Ballers and Room 104.

Some media journalists, including one from Agence France-Presse, received emails from an unidentified address boasting of the breach and proposing sharing unaired content from Game of Thrones.

“Any intrusion of this nature is obviously disruptive, unsettling and disturbing for all of us,” HBO chief Richard Plepler said in a memo to staff.