HBO Spain and Nordics accidentally made the next episode of Game of Thrones available to subscribers for an hour, before taking it down, the Associated Press reported.
The episode runs for 71 minutes, according to the report, and it was only set to become available on 21 August.
HBO Europe said the error appears to have originated with a third-party vendor. The episode was removed as soon as it was recognised, it said.
It added that this issue was not connected to the recent attack on HBO US.