"Sadly, it seems the leaked four episodes of the upcoming season of Game of Thrones originated from within a group approved by HBO to receive them. We're actively assessing how this breach occurred."
Fans of the show, which follows the ambitions and betrayals of competing noble factions and families in the fantasy world of Westeros, now face the daunting task of avoiding spoilers online as the first four episodes are released over the course of the month.
Episodes beginning this year's season are titled The Wars to Come, The House of Black and White, High Sparrow and The Sons of the Harpy.
They had been downloaded more than 550,000 times as of early Sunday morning, Variety reported, citing the piracy-tracking company Excipio.
"Sadly, it seems the leaked four episodes of the upcoming season of Game of Thrones originated from within a group approved by HBO to receive them. We're actively assessing how this breach occurred," HBO said in a statement.
The series is the most illegally downloaded program in the world.
Anti-piracy company Irdeto said that episodes from Game of Thrones' first four seasons were illegally downloaded more than seven million times between February and April 2015.
The astounding figure is a 45 per cent jump over the same period from 2014 for the show, which debuted in 2011.
Brazil and France are the top two countries by illegal downloads of the series inspired by George R R Martin's Song of Ice and Fire novels. They are followed by the US, Canada and the UK.
The Walking Dead, with 5.7million illegal downloads from February to April, was the second-most pirated show.
HBO planned today's premier to air across 170 countries at the same time in an effort to combat international piracy of the show.
- Daily Mail
