WARNING: Disturbing content.

AN EAST London street mural painted six years ago has sparked an ugly debate about anti-Semitism in the UK Labour Party as shocking comments are uncovered on private Facebook groups.

Labour leader Jeremy Corbyn has been accused of tolerating anti-Semitism after he previously supported “freedom of expression” for the artist behind a mural many regard as blatantly anti-Semitic.

It comes as an investigation by The Sunday Times revealed thousands of anti-Semitic, violent and racist comments on 20 of the biggest pro-Corbyn Facebook groups, sparking fears about the extent of the insidious force within the party membership.

Some of the most shocking include a comment that Nazi leader Adolf Hitler should have “finished the job” and another declaring the death of six million Jews was a “lie”, the newspaper reports.

The groups have 400,000 members between them, including at least 12 top leadership aides.

A Labour Party spokesman said the groups were not affiliated or backed by the party in any way and it is committed to campaigning against anti-Semitism.

OUTRAGE OVER ‘ANTI-SEMITIC’ MURAL

The ugly claims exploded into the spotlight after a comment Mr Corbyn made in 2012 while serving on the backbench recently resurfaced online.

At the time, an artist known as Mear One faced having his mural removed by a London council for being “anti-Semitic” following public complaints.

“Tomorrow they want to buff my mural Freedom of Expression. London Calling, Public art,” he wrote.

Jeremy Corbyn replied: “Why? You are in good company. Rockerfeller [sic] destroyed Diego Viera’s [sic] mural because it includes a picture of Lenin.”

The picture, called “Freedom for Humanity”, shows six cartoonish depictions of apparently Jewish men with hooked noses and glasses playing Monopoly on the backs of black and brown-skinned people with the Illuminati eye symbol shining above.

At the time, the artist said the picture is about “class and privilege” and included “Jewish and white Anglos”.

Following the recent outrage, Mear One defended the article further on the website of conspiracy theorist David Icke — who famously believes the royal family are shapeshifting reptilian lizards.

He also said on Facebook the picture was subject to “false accusations and gross misinterpretations” and was done following 9/11, the GFC and Occupy movement.

“All my growing fears and frustrations with the war in Afghanistan and Iraq, the ever-expanding coffers of the 1 per cent bankster elite profiting from the military industrial complex at the expense and enslavement of the working class were confirmed,” he said.

But the picture sparked outrage from other Labour MPs, the public and the Jewish community, who were shocked at the image and regarded it as blatantly anti-Semitic.

Mr Corbyn apologised for not looking closely at the “deeply disturbing and anti-Semitic” image and said he was committed to stamping out “pockets” of anti-Semitism in the party he now leads.

However the apology hasn’t gone far enough for some, including the Campaign Against anti-Semitism, which has planned a rally for April 8 to protest the issue. It claims Mr Corbyn has allowed the party to become a “safe haven for racists”.

“He is at home among them, having spent his political career seeking out and giving succour to Holocaust deniers, genocidal anti-Semitic terrorist groups and a litany of Jew-haters,” the group said.

It follows a combined protest last week organised by the Board of Deputies of British Jews and The Jewish Leadership Council who claimed “repeated institutional failure” to address the issue in the party.

Mr Corbyn has reportedly deleted his personal Facebook page, however his professional page hosted a Passover message saying that anti-Semitism was “sometimes harder to see it when it’s closer to home”.

“We all need to do better. I am committed to ensuring the Labour Party is a welcoming and secure place for Jewish people,” he said.