Police investigating alleged anti-Semitism by members of the Labour Party have passed five files on to the Crown Prosecution Service, Scotland Yard chief Dame Cressida Dick said today.

Lawyers will now decide whether to bring criminal charges against former party members accused of committing hate crimes.

The Met Commissioner told LBC radio that six people were arrested last year as part of the inquiry, and that five files have now been handed to the CPS.

An investigation was prompted by an internal Labour dossier detailing anti-Semitic messages on social media allegedly posted by Labour Party members, which was obtained by the radio station in September 2018.

It was claimed the documents included details of 45 cases, including one which allegedly read: “We shall rid the Jews who are a cancer on us all.”

Specialist Met officers assessed all the material provided and launched a criminal investigation into some of the allegations.

Dame Cressida told host Nick Ferrari today: “It is for the CPS to decide. It is a very complex crime type, to be honest — there is a lot for them to look at and a lot for them to consider as to whether there is either sufficient evidence to charge and whether it is in the public interest so to do.”

Files against five men, in their forties, fifties and sixties, from addresses including Newham, Tunbridge Wells, Birmingham and Bradford and a woman, in her seventies, from Wandsworth were submitted to the CPS on September 27 last year.

They are accused of publishing or distributing material likely to stir up racial hatred contrary to the Public Order Act 1986.

Scotland Yard said today: “On September 4, 2018, the Met Commissioner was handed a folder of paperwork following a radio interview with LBC radio.

“The complainant alleged that the documentation included evidence of anti-Semitic hate crimes. We will not comment further on the details of our investigation.”

The Labour Party has previously welcomed the police probe and said: “Anti-Semitism has no place in our society and we are committed to challenging and campaigning against it in all its forms.”

The party is also being investigated by the Equality and Human Rights Commission into other allegations of anti-Semitism.

The investigation is considering whether “unlawful acts have been committed by the party” and “whether the party has responded to complaints of unlawful acts in a lawful, efficient and effective manner”.

At a hustings in Westminster last night, candidates fighting to succeed Jeremy Corbyn as party leader faced questions over the anti-Semitism allegations which have engulfed Labour.

According to the Jewish Chronicle, MP Lisa Nandy said there had been a “collective leadership failure to acknowledge the anti-Semitism crisis”.

She was said to have gained ground last night after impressing fellow MPs. Former Labour minister Peter Hain said she had “stunningly persuasive appeal”.

Shadow Brexit secretary Sir Keir Starmer is the early frontrunner in the race, ahead of shadow business secretary Rebecca Long Bailey.

The new leader will be announced on April 4.