Hackers claim to have stolen the script of an as-yet unaired episode of 'Game of Thrones', as part of a data breach at US TV network HBO.
The group has already posted episodes of HBO shows 'Ballers' and 'Room 104' online. It claims to have obtained 1.5TB of data from the breach, and said it would release more material soon.
HBO confirmed that it has been the victim of a "cyber incident".
"We immediately began investigating the incident and are working with law enforcement and outside cybersecurity firms," it added in a statement. "Data protection is a top priority at HBO, and we take seriously our responsibility to protect the data we hold."
In an email to employees, HBO's chairman and chief executive said the breach was "obviously disruptive, unsettling, and disturbing for all of us."
The people behind the hack sent a statement to Entertainment Weekly.
"Hi to all mankind," it reads. "The greatest leak of cyber space era is happening. What's its name? Oh I forget to tell. Its [sic] HBO and 'Game of Thrones'....!!!!!
"You are lucky to be the first pioneers to witness and download the leak," it goes on. "Enjoy it & spread the words. Whoever spreads well, wi [sic] will have an interview with him. HBO is failing."
'Game of Thrones' is one of the most popular TV shows on the planet, so a breach of this kind is a huge blow to HBO (and Sky, who airs the show in the UK). Episode four of the seventh and penultimate series will air on Monday morning on Sky Atlantic.