An unaired episode of Game of Thrones appeared on the internet early this morning. While HBO’s servers were breached earlier this week, The Verge has learned that this episode leak was not part of that successful hacking attempt. Sources familiar with HBO’s security breach tell The Verge that a leak from a distribution partner is the source of this episode appearing online.

The distribution partner is Star India, and the company’s logo appears watermarked throughout the leaked episode. A Star India spokesperson confirmed the leak in a statement to The Verge. “This confirms the compromise of episode 4 of Game of Thrones Season 7, earlier this afternoon,” says a Star India spokesperson. “We take this breach very seriously and have immediately initiated forensic investigations at our and the technology partner’s end to swiftly determine the cause. This is a grave issue and we are taking appropriate legal remedial action.”

A freely available MP4 was to blame

Star India appears to have leaked the episode online through its own website. Smartprix spotted a direct link to the MP4 of the episode over at Star India’s own distribution site, allowing people to download Game of Thrones freely before sharing it with Google Drive links on Reddit.

HBO has struggled to run its own operations in India, and handed off distribution duties to Star India back in 2015. While additional episodes could leak from this particular distribution partner, it appears that the HBO hackers haven’t managed to obtain full episodes. Hackers reportedly stole 1.5 terabytes of data, but have only published scripts for upcoming episodes.

Either way, a leak from a distribution partner is yet another headache for HBO that has struggled with Game of Thrones leaks over the years. The first four episodes of season 5 leaked online, thanks to advance screeners that are sent out to members of the press. A HBO subsidiary also released a season 6 episode a day early.

Update, August 5th 12:45AM ET: Star India statement added to story, and additional details on leak.