The BBC has gone to a US court in a bid to track down the source of a Doctor Who leak earlier this year and is asking technology giant Microsoft for information.

Footage from Jodie Whittaker's upcoming debut as the first female Time Lord in the revered sci-fi franchise was leaked online.

The 53-second clip and two still images of Whittaker were shared in June.

According to legal documents lodged in Washington, the footage was stored and shared on Microsoft-operated file-hosting service OneDrive.

The documents say the BBC, referred to as BBC Worldwide Limited t/a BBC Studios (Distribution), is asking the court to subpoena Microsoft under the Digital Millennium Copyright Act (DMCA).