Peter Capaldi debuted as the new Doctor one month earlier than originally intended, as unfinished materials of "Doctor Who" Season 8 were leaked online.

Episode 1, "Deep Breath," is already on video piracy websites after security at BBC Worldwide was breached. Although it's not the final product, the leaked footage shows the full premiere episode, though with a rough edit.

RadioTimes reportedly has seen the black-and-white footage with the BBC Worldwide watermark on the video. It uses the title sequence from the last show with Matt Smith as a placeholder, and visual effects are yet to be added.

The same security lapse is blamed for other leaks that emerged last Monday, including five "Doctor Who" Season 8 scripts and dozens of other documents. Videos of subsequent episodes may surface later. Oddly, the incident appears similar to the leak of the premiere episode of the new "Doctor Who" era in 2005, with Christopher Eccleston. That leak happened 20 days before the episode was broadcast.

A BBC Worldwide representative said the company is conducting security investigations to track the breach, while the original content was removed from servers that were disabled last week. At the same time, he apologized to the fans and thanked them for trying to keep fan websites spoiler-free. Due to the incident, the BBC has launched a campaign on social media with the tag #keepmespoilerfree to discourage those in possession of the leaked content, which includes videos and scripts, from sharing it.

"Deep Breath," with Peter Capaldi and Jenna Coleman, premieres Aug. 23 as the first episode of the new "Doctor Who" Season 8 on BBC1.