Ruth Jones has revealed she enlisted the help of her nine-year-old niece in a bid to keep the Gavin & Stacey reunion under wraps.

The beloved sitcom will return for a Christmas special, allowing fans to catch up with the weird and wonderful cast of characters after a nine-year break.

Jones stars in and co-created the show alongside James Corden and the pair announced its return in May.

Ruth Jones comments
Joanna Page (left) and Ruth Jones during filming for the Gavin & Stacey Christmas special (Andrew Matthews/PA)

Jones, who plays Nessa, has now revealed the lengths she went to to keep Gavin & Stacey’s return a secret.

On a reconnaissance trip to the Welsh town of Barry, where the show is set, Jones took her nine-year-old niece to use as a cover story in case she was spotted by fans.

Jones was there to speak to Glenda – who owns the house used by Stacey’s mother Gwen in the show – about using the property again for the Christmas special.

Jones admitted she felt “ashamed” at using her niece but said it was necessary to keep the show’s return a secret.

She said: “When I’ve been back to Barry sometimes there are people who are taking photos of the outside of the house and, if they see me, they sometimes want to take photos. If they see me on my own, it might start suspicions going.

Ruth Jones comments
James Corden and Ruth Jones co-created Gavin & Stacey, which has since become one of the UK’s most beloved sitcoms (Yu Mok/PA)

“So I took my nine-year-old niece, who called the show ‘Gayin and Stacey’, she doesn’t know anything about it – ‘Let’s show you where Auntie Ruth used to film a television programme’.

“So, I took her and had some photos taken outside so I could just say ‘I’m just showing my niece’.”

Jones also had to tell a white lie to her friends, who asked abut her frequent trips to Los Angeles to write the show with Corden.

Corden, whose busy schedule hosting The Late Late Show complicated matters further, would squeeze in writing on his days off.

Jones flew to California in September last year before returning in February, arousing the suspicions of her friends.

Jones said: “My friends were saying to me ‘You’re going out to LA again?’ and I went ‘Yeah’ and they went ‘Is it for work?’ and I went ‘No, no just going out for a little holiday’. ‘Oh, you like it out there, don’t you?’ ‘Yeah, yeah, it’s nice’.

“The truth was we weren’t lapping up the LA sunshine, we were stuck indoors … not stuck, we were indoors writing.”

Gavin & Stacey stars Mathew Horne and Joanna Page as a young couple who fall in love following a whirlwind romance.

The show features a strong supporting line-up of memorable characters, including Rob Brydon’s eccentric Uncle Bryn and Alison Steadman’s over-protective mother, Pam.

Larry Lamb and Melanie Walters also star.

Gavin & Stacey returns to BBC One on Christmas Day.