The investigation will look into whether the populist party, which had been surging in the polls, breached the UK's electoral funding and donations laws.

In short:

London’s Metropolitan Police say they will carry out a criminal investigation whether Reform UK breached electoral funding laws.

It follows an undercover investigation by reporters that aired last week which captured leader Nigel Farage and his aides on camera talking about foreign donations.

Reform UK denies wrongdoing and says it will fully cooperate with the police investigation.