Keira Knightley illuminated the red carpet at the premiere of her new film Official Secrets – months after giving birth.

The British actress, 34, wore a white midi-dress with a white lace overlay as she arrived at the European premiere at the Embankment Garden Cinema in London.

Official Secrets European Premiere – BFI London Film Festival 2019
Keira Knightley at the European premiere of Official Secrets (David Parry/PA)

Knightley’s billowing outfit also featured elaborate floral designs and she completed the look with gold sandal-like high heels.

She is believed to have welcomed her second child with husband James Righton, formerly of the new-rave band Klaxons, in recent months.

The pair married in 2013 and welcomed their first child, a daughter called Edie, in 2015.

Official Secrets European Premiere – BFI London Film Festival 2019
Keira Knightley signs autographs for fans (David Parry/PA)

In her latest big-screen venture, Knightley plays Government Communications Headquarters (GCHQ) translator Katharine Gun, who in 2003 leaked a classified email that urged spying on members of the UN Security Council to push the Iraq War.

In doing so, she risked her career and put her life on the line.

The star-studded British cast includes Ralph Fiennes, Matt Smith and Matthew Goode, although Knightley was the only one to attend the red carpet.

Official Secrets European Premiere – BFI London Film Festival 2019
Keira Knightley and whistleblower Katharine Gun (David Parry/PA)

The email in question called for British help to bug the homes and offices in New York belonging to United Nations diplomats from six countries whose support over the invasion of Iraq would be vital.

It became front-page news on a national newspaper and Gun was charged with breaking the Official Secrets Act.

Official Secrets is released in UK cinemas on October 18.