UK police probe Labour Party 'anti-Semitic hate crimes'
"A criminal investigation has commenced into some of the allegations within the documentation," London's Metropolitan Police said in a statement on Friday.
The probe comes two months after a leaked dossier was handed to Britain's top police officer Cressida Dick at a national talk radio station.
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Police are seeking early advice from the Crown Prosecution Service (CPS), England's state prosecutors, which decides on whether to bring criminal charges once an investigation is complete.
"On Tuesday 4 September, the Met commissioner was handed a folder of paperwork following a radio interview with LBC," the Met Police said.
"The complainant alleged that the documentation included evidence of anti-Semitic hate crimes.
"The contents have been examined by specialist officers. A criminal investigation has commenced into some of the allegations within the documentation. Early investigative advice is being sought from the CPS."
The police said they would not comment further on the investigation.
LBC had received a dossier detailing 45 cases involving messages posted by Labour party members on social media.
Labour, led by veteran socialist Jeremy Corbyn, said they had not been contacted by the police but stood ready to co-operate with the investigation.
"The Labour Party has a robust system for investigating complaints of alleged breaches of Labour Party rules by its members... Where someone feels they have been a victim of crime, they should report it to the police in the usual way," a spokesman said.
Allegations of anti-Semitism have been a problem for Corbyn ever since his improbable leadership win in 2015.
He has also come under prolonged attack for refusing to adopt fully the International Holocaust Remembrance Alliance (IHRA) definition of anti-Semitism in Labour's new code of conduct.
Critics of the IHRA definition say it conflates anti-Semitism with legitimate criticism of Israel.
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"When some try to force the Labour party into using as its litmus test a definition of anti-Semitism that goes far beyond anti-Jewish animus to include anti-Zionism, we must raise our voices and decry these efforts," members of the opposition Joint List wrote in the letter to The Guardian.
Corbyn has also been accused of allowing anti-Semitism to spread in the left-wing party.
Corbyn has said there had been 300 internal party referrals for anti-Semitism since 2015, around half of which led to expulsions or resignations.
However, he said that some of the accusations were "overheated rhetoric" and that he would not accept that a Labour government would represent "any kind of threat" to Jews in Britain.
"I do acknowledge there is a real problem that Labour is working to overcome," Corbyn wrote in a guest column in The Guardian last month.
"And I accept that if any part of our national community feels threatened, anxious or vulnerable, not only must that be taken at face value but we must all ensure that those fears are put to rest," he added.
But Labour is not the only British party plagued with racism and religious bias. The Conservative party has been long criticised for being Islamophobic.
Baroness Sayeeda Warsi in July joined the Muslim Council of Britain, the Muslim Women's Network and British Muslims for Secular Democracy - as well as other voices - in calling for a complete inquiry into Islamophobia in the Tory party.
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"The Muslim Council of Britain has called for an inquiry; the Times published a leader urging the party to 'set Muslim minds at rest'; and Lord Sheikh warned that bigotry was a 'matter of grave concern', the Muslim Women's Network UK, British Muslims for Secular Democracy and others have supported calls for an inquiry and yet absolutely nothing tangible has happened," she said.
Agencies contributed to this report