A Hollywood star most famous for his role in Pirates of the Caribbean has swapped Los Angeles for Thanet.

British actor Stephen Graham is filming a true-life screenplay in Margate to give a voice to vulnerable and damaged child sex abuse victims.

His journey from California has ended with his arrival at Ramsgate's Royal Harbour Hotel, ready to start filming with actress wife Hannah Walters in Margate on Friday.

They are both playing main parts in campaign film Gaslighting, written and directed by award-winning Thanet filmmaker Elaine Wickham.

The contrast for Stephen could barely be more acute. From filming all-action scenarios for a multi-million pound internet trailer for on-screen blockbuster game Call of Duty - featuring combat fantasies and involving jumping on and off helicopters and motorbikes - he is in Thanet to play the father of a damaged and troubled young girl.

Stephen, 40, is known as sidekick Scrum to Johnny Depp's Captain Sparrow in Pirates of The Caribbean: On Stranger Tides, as Tommy in the film Snatch (2000) and as Andrew "Combo" Gascoigne in the 2006 British indie film This Is England.

He has been directed by Martin Scorsese, as Al Capone in HBO's series Boardwalk Empire, was in Gangs of New York alongside Leonardo DiCaprio and played Jerry Westerby in Tinker, Tailor, Soldier, Spy (2011).

But like Elaine and the rest of her film crew and cast, he and Hannah are passionate about the Clean-cut Pictures project which puts the spotlight on the link between child abuse and youth offending.

The term "gaslighting" arose from Ingrid Bergman's 1944 film Gaslight, and describes a pattern of psychological abuse in which the victim is gradually manipulated into doubting his or her own reality.

It was through Hannah, known for films This Is England (2006), Filth and Wisdom (2008), the TV drama The Antiques Rogue Show (2009), and as DC Megan Riley in ITV's Whitechapel, that the couple became involved.

Stephen, Hannah and Elaine are all former students of Sidcup's Rose Bruford College of Theatre and Performing Arts. For 20 years, Hannah had remained in regular contact with another fellow student, the film's editor Emma Collins.

Hannah, also 40, learnt about the film as they communicated on Facebook and said she was "knocked sideways" when she read Elaine's "beautifully written, poignant" script. She said: "It is composed so artistically, yet it hits home."

She jumped at the invitation to play the mother of the 12-year-old girl whose story is the subject of Gaslighting.

Stephen said: "I asked Hannah what she was reading, she told me it was really good, I read it and felt the same and asked 'who is playing your husband?'

So affected was he, that he asked if he could take on the part.

"This all happened at the end of last year," said Hannah. "It was a challenge trying to organize filming between our schedules but we have managed to pull it together."

"This film is so important because it makes these young people aware that they have a voice..." - actor Stephen Graham

Hannah said each one of the 40-strong company were donating their time and talents free "because we are passionate about this project, we believe in it so strongly", describing Elaine's endeavour as "admirable and brave".

"This is an issue as a parent that you don't want to think about, but you have to," she added.

Stephen said: "This film is so important because it makes these young people aware that they have a voice. It is making people aware of what can happen."

They share a sense of obligation to use their role as actors, and prominence in the public eye, to "make a social comment and bring awareness to the project and the themes behind it".

Playing the mother is a challenge for Hannah. Stephen said the character is a "polar opposite" from his wife. Hannah was "all about her kids", committed, loving, caring, everything that defines the ideal of motherhood.

Hannah said: "This is an unusual role for me, it is a challenge and great for me, I am more used to playing abrupt, forthright characters. This mother is very vulnerable and depressed."

Stephen has been watching Benefit Street as research for his character, an unemployed man who does not like his partner's daughter, and is completely devoid of an inclination to work.

This is quite the opposite to how he and Hannah were brought up, with working class parents who instilled a strong work ethic.

Once filming is complete - by the weekend - they are looking forward to returning home to their own children, Grace, nine, and Alfie, seven, in a quiet, traditional Leicestershire village where life suits them to a tee.

This year they will both be giving further, whole-hearted support for Stand Up To Cancer. Hannah lost both her parents prematurely to the disease, her father died when he was 30 and her mother when she was 58.

Stephen is soon to start work with Jim Broadbent on the family comedy Get Santa, and is returning as Scrum in the next Pirates of the Carribean, due for release in 2016.

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