02/04/2016 21:17 BST | Updated 02/04/2016 21:26 BST

Making A Murderer Demonstrators Welcome Miriam Margolyes At London Protest

'People have got to know what's going on.'

Harry Potter actor Miriam Margolyes joined protestors in London on Saturday to demonstrate against the imprisonment of two men featured in the Netflix documentary Making A Murderer.

The 74-year-old actor, who joined demonstrators in Parliament Square, hit out at the American criminal justice system.

"People have got to know what's going on because this corruption and injustice affects everyone in every country," Margolyes told The Press Association.

Demonstrators held banners with slogans such as: "Injustice anywhere is a threat to justice everywhere. Stand united."

They also wore T-Shirts, which read: "Free Steven Avery and Brendan Dassey."  

Making A Murderer follows the story of Steven Avery, who was found guilty of the murder of Teresa Halbach.

Both he and his nephew Brendan Dassey are currently serving life sentences in US jails for Halbach's murder.

But the popular documentary, which was filmed from the defence team's perspective, included claims that Avery and Dassey were framed for the murder, leading many to question the legitimacy of their sentencing.

Last week, it was revealed that the lawyer representing Avery said she had “new suspects” in the infamous case.

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