The Metropolitan Police has widened an existing criminal investigation involving Reform UK after assessing fresh allegations concerning political donations and polling.
The force said detectives had reviewed information provided following an undercover Channel 4 News broadcast and concluded that there were potential offences requiring investigation.
The Met said the new allegations were similar in nature to matters already being examined by its Special Enquiry Team in relation to donations made to Reform UK and would therefore form part of that ongoing investigation.
Reform UK has denied wrongdoing and said it will cooperate fully with police.
Fresh allegations added to existing police investigation
The latest development follows an undercover investigation in which reporters posed as representatives of a prospective foreign donor.
The broadcast raised allegations about discussions concerning political funding and the financing of opinion polling.
Those allegations have not been proven and no finding of criminal wrongdoing has been made against Reform UK or any individual.
In a statement reported by Reuters, the Metropolitan Police said detectives had determined that there were potential offences requiring investigation and that the matters were similar to issues already under examination by the force's Special Enquiry Team.
The force is now seeking relevant footage from the broadcast and is liaising with the Electoral Commission and Crown Prosecution Service as inquiries continue.
Reform denies wrongdoing
Reform UK has strongly denied any wrongdoing and has described the undercover operation as a hoax.
The party said it would cooperate fully with the police investigation and would not comment further while inquiries were ongoing.
Party leader Nigel Farage has previously denied that Reform accepted any unlawful foreign donation and has rejected suggestions that electoral law was breached.
Senior figures stepped down
Two senior Reform figures, Dan Jukes and James Orr, stepped down from their roles following the undercover broadcast.
The footage was reported to show discussions about ways a purported American businessman could support polling or political activity connected to Reform UK.
Those discussions form part of the allegations now under police scrutiny, but the existence of an investigation does not establish that any offence was committed.
Existing investigation already confirmed
The existence of a wider Metropolitan Police investigation into Reform-related donations had already been acknowledged in Parliament.
In a written parliamentary answer published on 7 September, the Speaker's Committee on the Electoral Commission said the Metropolitan Police Service had issued a statement about an ongoing police investigation and that the Electoral Commission could not comment further.
A separate Government answer published on 8 September confirmed that the Met's Special Enquiry Team leads the force's response to electoral crime and politically sensitive investigations.
Political finance under growing scrutiny
The police investigation comes amid wider political scrutiny of the rules governing donations to political parties and candidates.
UK law restricts who can make political donations, while parties and regulated individuals are subject to reporting and transparency requirements.
The Government is also pursuing changes to political finance rules, including tighter controls intended to prevent foreign money entering UK politics.
For Reform UK, the widening police inquiry adds further pressure at a time when the party's finances and fundraising arrangements are already under intense political and regulatory scrutiny.