Scotland Yard has opened a criminal investigation into allegations of antisemitic hate crimes linked to Labour party members, according to the commissioner of the Metropolitan police.

Cressida Dick said officers had reviewed a leaked party dossier detailing 45 cases of alleged antisemitism that was passed to her in September by the radio station LBC.

The UK’s most senior police officer told the BBC she believed there could be a case to answer and, as a result, the force was consulting with prosecutors on the next steps.

“We have been assessing some material that was passed to me, in a radio studio of all things, about two months ago and we are now investigating some of that material because it appears there may have been a crime committed,” Dick said.

“We are liaising immediately with the Crown Prosecution Service and I hope we will be able to clear that up very quickly.”

LBC received an internal Labour dossier detailing 45 cases involving messages posted by party members on social media, including one that read: “We shall rid the Jews who are a cancer on us all.”

The broadcaster passed the leaked material to the former senior police officer Mark Chishty to review, who said 17 instances should have been reported to the police for investigation, and another four were potential race hate crimes.

These four included the message detailed above; the sharing of a link to an allegedly antisemitic blog; and an entry referring to “a Zionist extremist MP … who hates civilised people, about to get a good kicking”.

Another related to a Labour councillor being accused of putting a child through “10 years of hell”, slurring him racially and calling him a Jew boy.

Tom Watson, Labour’s deputy leader, said the announcement was “thoroughly depressing, although sadly I am not surprised. All I can say to you again, if people have committed hate crimes they need to be dealt with by the full force of the law.”

He added that he hoped the Met inquiry would “silence a very small number of people who believe that antisemitism doesn’t exist in my party, or in other parties”.

The dossier was handed to Dick on 4 September. A spokesman for the Met added: “The complainant alleged that the documentation included evidence of antisemitic hate crimes. The contents have been examined by specialist officers. A criminal investigation has commenced into some of the allegations within the documentation.

The Labour party said it had not been contacted by the police but was ready to cooperate with the investigation. The Labour party has a robust system for investigating complaints of alleged breaches of Labour party rules by its members,” a spokesman said. “Where someone feels they have been a victim of crime, they should report it to the police in the usual way.”