Sheridan Smith looked unrecognisable as she transformed into grieving mother Ann Ming while filming for the upcoming real-life drama series I Fought The Law in Newcastle on Monday.
The actress, 43, was seen shooting tense storylines as she was thrown out of court following an emotional outburst.
Her character Ann is a real woman who campaigned for 15 years to bring her daughter's murderer to justice. She got the UK's 800-year-old 'double jeopardy' law overturned following the murder of her daughter Julie Hogg.
Sheridan was seen battling security staff as she was forced out of the building while grimacing, before having a heated argument with a man in a grey suit on the street outside.
To transform into Ann she wore a curly short blonde wig and had on a navy coat and flowery blouse.
She looked hugely emotional and angry as she filmed scenes near the courthouse.
Sheridan Smith looked unrecognisable as she transformed into grieving mother Ann Ming while filming for the upcoming real-life drama series I Fought The Law in Newcastle on Monday
The actress, 43, was seen shooting tense storylines as she was thrown out of court following an emotional outburst
Her character Ann is a real woman who campaigned for 15 years to bring her daughter's murderer to justice (Ann see right in real life)
Her latest filming comes just after she made her return as Smithy's sister Rudi in the Gavin & Stacey Christmas special.
She made a brief appearance in one scene at the start of Smithy's wedding to Sonia.
Julie was murdered by William 'Billy' Dunlop but jurors failed to find him guilty - twice.
This meant that even when Billy confessed, he could not be trialed again, in accordance with the law at the time.
However, after almost 17 years of campaigning with her husband Charles, who died in 2013, Ann got this law amended, and Billy is currently serving a life sentence.
Julie, who was a mother to three-year-old, Kevin, and a wife to 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 there by Billy.
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 had strangled and then sexually mutilated Julie, before hiding her body under the bath in her own house.
She looked a far cry from her usual self (Sheridan pictured in April)
Sheridan was seen battling security staff as she was forced out of the building while grimacing, before having a heated argument with a man in a grey suit on the street outside
To transform into Ann she wore a curly short blonde wig and had on a navy coat and flowery blouse
She added clumpy black heels to the look and looked hugely emotional and angry near the courthouse
Julie was murdered by William 'Billy' Dunlop but jurors failed to find him guilty - twice
This meant that even when Billy confessed, he could not be trialed again, in accordance with the law at the time
Ann, now in her late 70s, is acting as a consultant throughout the production process of I Fought The Law.
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.
However, after almost 17 years of campaigning with her husband Charles, who died in 2013, Ann got this law amended, and Billy is currently serving a life sentence
Julie, who was a mother to three-year-old, Kevin, and a wife to 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 there by Billy
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 had strangled and then sexually mutilated Julie, before hiding her body under the bath in her own house
Ann, now in her late 70s, is acting as a consultant throughout the production process of I Fought The Law
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'
Speaking about the role, Sheridan said: 'I am so honoured to have been asked to play the role of Ann Ming'
They filmed several scenes and for another she changed into a black coat and scarf
She was seen chatting to the other cast
And was surrounded by photographers for another scene
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
The law came into effect in 2005, and since then retrials have been allowed in cases where 'new, compelling, reliable and substantial evidence' has comes to light
Sheridan looked completely different when out filming
Her blonde wig completely changed her look
She looked distressed as she was approached by photographers
And later looked dejected as she sat by the court house
'Having such an iconic and talented actress portray me is truly wonderful.'
Speaking about the 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.'
What is double jeopardy?
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 by Sir 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 then retrials have been allowed in cases where 'new, compelling, reliable and substantial evidence' has comes to light.