Gavin & Stacey star Laura Aikman has revealed more behind the scenes secrets from the finale, after her character’s return was kept hidden from fans.

Laura made her return as Smithy’s girlfriend Sonia in the Christmas Day finale, providing a shock plot twist for fans when it was revealed in the opening scenes that she and James Corden’s character were preparing to marry.

Laura’s casting was kept secret so as not to spoil the curveball for fans, with the actress forced to stay in a separate hotel to the rest of the cast during the shoot and sign an NDA.

But the actress has been excitedly sharing a look at her time on set in the days since the finale aired.

On Sunday Laura posted photos of her character’s wedding dress, revealing the incredible lengths cast and crew went to to keep Sonia’s return secret.

Sharing the Insta snaps of herself posing in her bridal gown on set, Laura explained: ‘We couldn’t go wedding dress shopping (because of the secrecy), so this was from Vinted, (it probably belonged to someone who watched the show!)’

+7
View gallery

Gavin & Stacey star Laura Aikman has revealed more behind the scenes secrets from the finale, after her character’s return was kept hidden from fans

‘Shout out to our costume designer #ShanJames who had to alter it massively as 48 hrs before we shot the wedding it didn’t fit.’

Incredibly, the original owner of the wedding dress was soon revealed, as the show’s costume designer Shan James replied to the post.

‘Thank you gorgeous lady! It was a pleasure to dress you an absolute pleasure even though it was a massive job altering that gorgeous dress for you,’ Shan told Laura before revealing where she bought the dress.

‘It was from FB Marketplace and the lady selling the dress thought I was ‘well dodgy’ when I was so secretive!!’

Shan added that she had received a message from the dress seller on Boxing Day, which she shared with Laura.

‘I just watched Gavin & Stacey and had the oddest feeling that was my wedding dress that Sonia wore – can I ask if that’s what you used it for?’ read the message.

Shan replied, writing: ‘Hi there! I tried to find these messages yesterday so that I could let you know exactly that!’

‘I couldn’t say a thing as it was extremely top secret and I couldn’t take Laura to any shop incase she was spotted. You can now tell the world! I had to alter it quite a lot to fit her but it was worth it I think. She looked gorgeous so thank you so much’.

+7
View gallery

On Sunday Laura posted photos of her character’s wedding dress, revealing the incredible lengths cast and crew went to to keep Sonia’s return secret

+7
View gallery

Sharing the Insta snaps of herself posing in her bridal gown on set, Laura explained: ‘ We couldn’t go wedding dress shopping (because of the secrecy), so this was from Vinted’

The delighted seller responded: ‘That is amazing, it’s my absolute favourite show! I had good bumps when I watched it!’

‘I noticed the panel in the back, Oh bless!This is so great I’m totally made up, thanks for letting me know what a cool job you have too! .’

Laura also revealed to fans how she had to wear a wig during filming, explaining:  ‘Our formidable make up designer #marcuswhitney found me this amazing wig, yes IT’S A WIG. It was fitted & styled by gorgeous @alisonwebbxxmakeup who also did my make up and hid with me.’

In response to a fan’s question on why she didn’t just show her natural hair, the actress revealed she was juggling multiple jobs. ‘my hair was dark for another job I was going back and forth from x’ she admitted.

After the show aired, Laura took to Instagram to share the adorable moment her parents discovered she was returning to the sitcom as Sonia while watching the finale.

+7
View gallery

Incredibly, the original owner of the wedding dress was soon revealed, as the show’s costume designer Shan James replied to the post

+7
View gallery

Shan added that she had received a message from the dress seller on Boxing Day, which she shared with Laura

Her appearance came as a shock to the nation, as Laura had been ‘hidden away’ in a separate hotel during filming, and she had signed an NDA preventing her from revealing she was returning.

As 12.5 million viewers gasped in shock at the big reveal, no one was more dumbfounded than her beloved parents – who had no clue she was making her big comeback.

Alongside the clip, she wrote: ‘The moment my family realise Sonia is ruining Christmas again…’

Gavin And Stacey director Christine Gernon also took to Instagram after the finale aired to reveal the extent of the extreme measures taken to her comeback secret under wraps.

Sharing a snap of Laura alongside Alison Steadman, who portrays Pam in the BBC show, the director quipped: ‘@lauraikman spent the whole g&s shoot being hidden away.

‘Staying in a different hotel, not allowed to come to wrap or screening parties so no one knew Sonia was back. Such a great reveal. And she’s amazing as both actor and person.’

+7
View gallery

Fans were left in shock at the start of the episode when it was revealed Sonia and Smithy were set to marry after Nessa proposed to him at the end of the 2019 Christmas special

+7
View gallery

Her appearance came as a shock to the nation, as Laura had been ‘hidden away’ in a separate hotel during filming, and she had signed an NDA preventing her from revealing her return

Gavin and Stacey: The Finale drew in a whopping 12.5 million viewers to become the most watched show on Christmas Day.

Viewers had been waiting for five years to learn the fate of the BBC sitcom’s beloved characters and see if Smithy had accepted Nessa’s proposal.

The final episode was hailed ‘perfect’ by viewers, who were left in tears as the long-running show finally aired its last episode after 17 years.

The BBC won the battle of the channels when it came to ratings as 10 million also tuned in to watch the return of Wallace & Gromit: Vengeance Most Fowl.