BBC Worldwide has appealed to Doctor Who fans for help after scripts from the new series were leaked online.
The new series of the long-running science fiction show returns to BBC1 on August 23, with Peter Capaldi starring as the time lord .
A spokeswoman for BBC Worldwide, the corporation's commercial arm, said: "BBC Worldwide is currently investigating a security issue around Doctor Who Series 8 where unfinished material has inadvertently been made public.
"We deeply regret this and apologise to all the show's fans, the BBC and the cast and crew who have worked tirelessly making the series.
"We would like to make a plea to anyone who might have any of this material and spoilers associated with it not to share it with a wider audience so that everyone can enjoy the show as it should be seen when it launches.
"We know only too well that Doctor Who fans are the best in the world and we thank them for their help with this and their continued loyalty."
It was reported the scripts for five episodes were leaked after being sent to BBC Worldwide's office in Miami for translation.
It was announced last week that St Helens raised novelist and screenwriter Frank Cottrell Boyce has scripted an episode of the new series - which features the voice of Peppa Pig.
It features a cast of young actors including Harley Bird, who landed a Bafta for voicing animated character Peppa, as well as Abigail Eames who featured in The Crimson Field, Ashley Foster from the The Woman In Black and Jaydon Harris-Wallace.
Cottrell Boyce, who wrote the opening ceremony for London 2012, has worked on films including 24 Hour Party People, about the Manchester music scene, and the Danny Boyle-directed Millions.
It is not clear if Cottrell Boyce's script is among those that have been leaked.