Their will they, won't they romance kept viewers guessing for years.

And as Gillian Anderson and David Duchovny reunited on the red carpet at the London premiere of The X Files: I Want To Believe, the two actors looked very close.

But there were some slight differences between the famous pairing - namely Gillian's bulging baby bump.

The pregnant actress, 39, is due to give birth to her third child later this year with partner businessman Mark Griffiths.

Reunited: Mulder and Scully - actors David Duchovny and Gillian Anderson at the premiere for The X Files: I Want To Believe

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David Duchovny signs autographs at the London premiere in London's Leicester Square

The red-haired actress looked stunning in a halternecked black and white print maxi dress.

She was joined by a grizzled looking Duchovny, 48 next week, as the pair reunited for the big screen version of the hugely successful television series.

The pair will reprise their roles as FBI Special Agents Fox Mulder (Duchovny) and Dana Scully (Anderson) in the second movie spin-off from the cult hit TV series.

The truth is in there: Gillian Anderson launches the second X Files film, and prepares for the birth of her third child

The paranormal X-Files movie continues after nine globally successful TV series, three Golden Globes, an Emmy and the first film - The X-Files in 1998, which made $187 million.

Duchovny, wearing a beige-coloured outfit, signed autographs and Anderson, wearing a flowing dress, waved at the crowd.

The pair spoke briefly outside the cinema in London's Leicester Square before going inside.

Starlets: Mary Elizabeth Winstead and Tudors actress Natalie Dormer provided the glamour at the premiere

Small brother: Chantelle Hayes of Big Brother and her escort for the evening arrived to bask in the spotlight

Created and executive produced by Chris Carter, the X-Files, which began in 1993, chronicles the lives and adventures of Fox Mulder and Dana Scully.

The two dissimilar FBI agents assigned to investigate unsolved cases within the Bureau - cases which often involve the paranormal, the supernatural and the inexplicable.

Girl power: Samantha and Amanda Marchant, and Tamara Ecclestone (right) and Petra Ecclestone pull out all the stops style wise

The film also stars Billy Connolly, Amanda Peet and Xzibit.

It promises to take the complicated relationship between Mulder (Duchovny) and Scully (Anderson) in "unexpected directions".

The film is being released in the UK and Ireland on Friday.

Among the stars on the red carpet were Death Proof actress Mary Elizabeth Winstead, Tudors actress Natalie Dormer and McFly stars Harry Judd and Tom Fletcher.

From dashing to dishevelled: David returns to his hotel after the premiere looking rather scruffy