Officers bailed over Police Federation fraud allegations
Three serving policemen and a retired police officer have been released on bail after being arrested in connection with alleged fraud involving the Police Federation of England and Wales.
Surrey Police are investigating an alleged transfer of about £1m to a charitable account in August last year.
One of those arrested is understood to be Will Riches, who quit as federation vice-chairman earlier this week.
Scotland Yard has said two of the men are Met police officers on secondment.
Two of the men are in their 40s and two are in their 50s.
The Police Federation, which represents thousands of officers of constable, sergeant and inspector rank, says it is co-operating with the inquiry.
"We are carrying out a detailed and thorough investigation into allegations of fraudulent activity involving significant amounts of money," said Detective Superintendent Karen Mizzi from Surrey police.
The federation's chairman, Steve White, general secretary, Andy Fittes, and treasurer, Martyn Mordecai, are understood not to be among those arrested, the BBC's Danny Shaw says.
The Independent Police Complaints Commission has also been notified.
The Police Federation of England and Wales first raised concerns with Surrey police - the federation's local force - on Tuesday.
The federation then made a formal allegation relating to accounts held by the Federation's Constables' Central Committee on Wednesday.
Det Supt Mizzi said Surrey police had contacted the relevant police forces to inform them of the arrest of their officers.
The force would also be contacting the Charities Commission, she said.