A new range of Xbox 360 titles were temporarily made available on Xbox One backwards compatibility over the weekend, including Rockstar's hit western Red Dead Redemption, Halo Wars, Tekken Tag Tournament 2 and Alan Wake's American Nightmare.
The games have since been removed, but were "accidentally" made downloadable by players who owned digital copies and followed certain steps to find them. Physical disc copies were not supported.
After the error was discovered, Microsoft reportedly attempted to stop users playing Red Dead Redemption by forcing an update that rendered it unplayable and switching the download files to Xbox 360 puzzle game Hexic HD.
Microsoft's Major Nelson also left this message on Reddit:
"Microsoft tests all Xbox 360 games with our emulator to ensure a quality experience across a breadth of titles. Due to an error, some of the games currently in test were accidentally made available. We have since removed access to those games, and apologize for any confusion this may have caused. We will have more information on upcoming releases soon."
The titles were the first to appear after Microsoft announced that it would no longer be rolling out monthly batches of backwards compatible titles, instead choosing to release backwards compatible games as and when they become available.
It remains unclear when the games will 'officially' be available on Xbox One.