Sheridan Smith looked unrecognisable in a short blonde wigon the set of new ITVdrama I Fought The Law on Monday.
The actress, 42, will portray mother and nurse Ann Ming in the real life series, who camaigned for 15 years tobring her daughter's murderer to justice.
Filming has just started in Hartlepool, County Durham and Sheridan bundled up in a beige trench coat over a blue gingham nurse's uniform, teamed with tights and slip-on shoes.
Ann campaigned for 15 years to change the centuries-old Double Jeopardy Law following the brutal killing of her daughter Julie Hogg in Billingham, County Durham, in 1989.
Her determination secured the conviction of William 'Billy' Dunlop, who admitted the murder while serving time for another crime.
Sheridan Smith looked unrecognisable in a short blonde wig on the set of new ITV Drama I Fought The Law on Monday
The actress, 42, will portray mother and nurse Ann Ming in the series, which has just started filming in Hartlepool, County Durham
Ann Ming campaigned for 15 years to change the centuries-old Double Jeopardy Law following the brutal killing of her daughter Julie Hogg in Billingham, County Durham, in 1989
The new scripts are based on Ann's book For The Love of Julie which follows how Ann and her family dealt with Julie's disappearance in Billingham, Cleveland in November 1989 after working her late shift at a local pizza parlour.
Julie, who was a mother to three-year-old, Kevin, and married to husband, Andrew, was only 22 when she died.
Tragically, Ann found Julie's body concealed in the bathroom of her terraced house in January 1990, 80 days after it was hidden behind the bath panel by her killer.
This was in spite of extensive searches of the property by police forensics teams in the days after her disappearance, who failed to detect her body.
Her daughter's killer strangled and then sexually mutilated Julie, before hiding her body under the bath in her own house.
Ann, now in her late 70s, will act as a consultant throughout the production process and will be played in the drama by Smith.
She said: 'My daughter's killer was wrongfully acquitted, and a number of years later confessed to her murder, for which he could only be prosecuted for perjury due to the 800-year-old Double Jeopardy Law.
'I wasn't going to let this stand in my way of getting justice for Julie. I'm overwhelmed that Sheridan Smith will be playing me.
'Having such an iconic and talented actress portray me is truly wonderful.'
Speaking about the new role, Sheridan said: 'I am so honoured to have been asked to play the role of Ann Ming, a mother so determined to fight for justice for her murdered daughter that she spent 15 years campaigning for the Double Jeopardy Law to be changed.'
She added: 'She is a truly courageous and remarkable woman to whom we all owe a debt of gratitude'
Sheridan looked tense while filming the drama and was joined on set by several male actors
She covered up her long brunette locks with a short blonde wig
A mother whose fight to bring her daughter's murderer to justice made legal history is being made into an ITV drama starring Sheridan
She bundled up in a beige trench coat over a blue gingham nurse's uniform, teamed with tights and slip-on shoes
Julie Hogg was murdered by Billy Dunlop in 1989. Her body was hidden under her bath
Ann, now in her late 70s, will act as a consultant throughout the production process and will be played in the drama by Smith
She said: 'My daughter's killer was wrongfully acquitted, and a number of years later confessed to her murder, for which he could only be prosecuted for perjury due to the 800-year-old Double Jeopardy Law.'
'I wasn't going to let this stand in my way of getting justice for Julie. I'm overwhelmed that Sheridan Smith will be playing me.'
'Having such an iconic and talented actress portray me is truly wonderful.'
What is double jeapordy?
Double jeopardy is the principle that you can't go on trial for the same crime more than once.
Its purpose was designed to protect the innocent against judicial tyranny that could see them convicted arbitrarily, even after being found not guilty by a jury.
In 2005, the Labour government repealed the law after a number of campaigns, which persuaded senior judges and legal figures that a more nuanced approach was needed to deal with complex cases.
One of these was a campaign by the family of the murdered teenager Stephen Lawrence in 1993.
Five suspects were charged but not convicted after an initial investigation.
In 1999, a public inquiry led bySir William Macpherson concluded that Metropolitan Police was institutionally racist.
As a result he that recommended double jeopardy be repealed in murder cases where extraordinary evidence later emerges.
The law came into effect in 2005, and since thenretrials have been allowed in cases where 'new, compelling, reliable and substantial evidence' has comes to light.
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Sheridan appears to be very busy with work, as alongside the new ITV role she has reportedly 'signed a deal' to return for the last ever episode of Gavin & Stacey.
The actress, 42, is said to be joining the iconic cast for the Christmas special as James' on-screen sister Rudi Smith, which will mark the finale of the beloved sitcom.
Despite recent reports Sheridan would not be involved, sources working on the BBC have been told informal discussions with the star have already taken place - as per The Mirror.
Just earlier this month, sources close to the award-winning actress told MailOnline there have been 'no conversations' about a return to the much-loved BBC sitcom, which James, 45, and co-writer Ruth Jones, 57, confirmed last month would be back for a final instalment on Christmas Day.
But now it seems things might have take a turn and there might be hope for a legendary reunion for the books.
'The script for Gavin & Stacey: The Finale includes all of the show's major players - including Smithy's sister Rudi. Nothing has been signed and conversations are still very much ongoing - especially as the filming date has not been set,' the source told the publication.
'But all of the stops are being pulled out to make sure the whole cast are there, and in the coming weeks the production team hope to pin down everyone's availability.
'Sheridan and James are still friendly - they recently bumped into each other at the Variety Club Awards and got on really well. So the hope is that she will be able to be part of it.'
Sheridan appears to be very busy with work, as alongside the new ITV role she has reportedly 'signed a deal' to return for the last ever episode of Gavin & Stacey
Sheridan played Ruth 'Rudi' Smith, known for her tumultuous relationship with James's character Smithy, plus their impromptu raps, and is a cult favourite with fans
The telly source added Sheridan did not appear in the Christmas Special episode in 2019 because her character was 'not part of the storyline', although this time it is a 'different story'.
MailOnline has contacted both Sheridan and BBC's representatives for a comment.
Sheridan played Ruth 'Rudi' Smith, known for her tumultuous relationship with James's character Smithy, plus their impromptu raps, and is a cult favourite with fans.
The actress dated James for two years between 2007-2009 and the pair are believed to be on good terms.
They both attended The Variety Club Showbusiness Awards at the end of April where James was the recipient of the Outstanding Global Achievements in Broadcasting, Acting and Comedy accolade.
James and Ruth confirmed the sitcom's return on social media with a post featuring the creators holding up a script titled Gavin and Stacey: the finale earlier this month.
Fans will finally discover whether or not Smithy and Nessa end up together and, potentially, find out what happened on that notorious fishing trip.
Unlike Sheridan, the show's main stars have been contacted to ensure their diaries are clear to film the final episode, which will air on Christmas Day on BBC1.
