British Labour Party leader Jeremy Corbyn. Photo: Reuters / Pierre Albouy.

British police said on Friday they had launched an investigation into alleged antisemitic hate crimes within the opposition Labour Party, after a report that Labour itself had found evidence of party members threatening politicians.

In recent years, Labour has been accused of harboring antisemitism and Jewish groups have accused Labour leader Jeremy Corbyn of not taking the problem seriously enough.

London’s Metropolitan Police began an inquiry after its chief, Commissioner Cressida Dick, was given a Labour Party dossier in September by London’s LBC radio that detailed 45 alleged cases of antisemitism, the station said.

It included a reported Facebook post from a party member saying that a Jewish Labour lawmaker would get a good kicking, and another post with a threat to throw two other members of parliament off the top of a building.

“A criminal investigation has commenced into some of the allegations within the documentation,” a police statement said.

Labour’s deputy leader Tom Watson said the allegations were “thoroughly depressing, although sadly I’m not surprised.”

“If people have committed hate crimes, then they need to be dealt with by the full force of the law. There’s no role for them in the Labour Party,” he told BBC Radio.

Corbyn acknowledged this year, after months of pressure, that antisemitism had surfaced within the party, and apologized for the pain it had caused.

But Jewish leaders criticized his response as a “disappointing missed opportunity.”

A report in February by the Community Security Trust, a charity that provides security advice to Britain’s Jewish communities, said anti-Jewish sentiment was becoming more commonplace.

It said publicity about alleged anti-Jewish sentiment in Labour had been partly to blame for a record number of antisemitic incidents in Britain last year.

Amanda Bowman, vice president of the advocacy group the Board of Deputies of British Jews, said there was a “deeply embedded culture of antisemitism in parts of the Labour Party, and Jeremy Corbyn has done close to nothing to address it.”