THE author of ITV’s Grace has dropped a hint about a surprise guest appearance ahead of the second series.

Film crews were spotted in Brighton earlier this week ahead of the much-anticipated return of the hit show.

Grace, an adaption of Sussex author Peter James’s international bestselling book Dead Simple, is one of ITV’s most successful dramas with more than eight million people tuning in to watch the first series.

The series stars Life on Mars actor John Simm as the protagonist, fictional detective Roy Grace.

Peter took to social media to the news of its return and dropped a hint about a potential guest appearance.

The tweet said: “#ITVGrace has resumed filming. If you are out and about in #Brighton you might be lucky to spot the cast and crew in action! Also there will be a very exciting cameo in series 2... who could it be.”

Fans of the show were quick to give their take on his cryptic tweet, with guesses including Jackie Weaver, Philip Glenister and even Peter James himself.

The second series will be made up of three 120-minute films - Not Dead Enough, Dead Man’s Footsteps and Dead Tomorrow.

The Argus: Grace is one of ITV’s most successful dramas with more than eight million people tuning in to watch the first series Grace is one of ITV’s most successful dramas with more than eight million people tuning in to watch the first series

Series producer Kiaran Murray-Smith also shared a photo on Twitter of the film crew gathered in a Brighton street as they prepared to shoot a scene.

Alongside the photo, he wrote: “Grace has officially started shooting again. Woo hoo!”

John Simm and his co-stars Richie Campbell and Line of Duty star Craig Parkinson were also mentioned in the tweet.

The first series of Grace was filmed in Brighton and Hove last year with city landmarks – including both piers and Hove’s beach huts – playing a starring role in the adaption.

Writer Russell Lewis said: "After the overwhelmingly positive audience response to the seaside noir of Dead Simple and Looking Good Dead ready to go, all at team Roy Grace are delighted to have been given the opportunity by ITV to return to Brighton (and Hove, actually!) to continue Roy's story with a new series of films based on Peter James best-selling novels.

"We’ll be shooting out of our Brighton HQ and all along and around the South Coast from late summer through to very late autumn.

He said that filming "may well be coming to a street near you" and told fans to keep their eyes peeled.