Prince Charles and close aide reported to police by pressure group Republic over cash-for-honours claims

The Prince of Wales and his aide Michael Fawcett have been reported to the police by a pressure group over the cash-for-honours allegations.

Graham Smith, chief executive of Republic, which campaigns for an elected head of state, said he had contacted the Metropolitan Police and reported both Charles and Mr Fawcett on suspicion of breaching the Honours (Prevention of Abuses) Act 1925.

Former royal valet Mr Fawcett is accused of promising to help secure a knighthood and British citizenship for a Saudi billionaire donor.

Mr Smith said: "Failure to properly investigate these matters will damage public trust in the police, the royals and the honours system.

"Time and again the royals blame their staff or associates for their own mistakes.

"It is difficult to believe Charles wasn't aware of these arrangements or promises. It's time the royals were personally challenged over their conduct."

Ex-Liberal Democrat MP Norman Baker has also written to the Met asking the force's Commissioner, Dame Cressida Dick, to launch a criminal probe.

A spokesman for Scotland Yard said: "We are aware of the media reports and await further contact in relation to this matter."

Mr Fawcett has stepped down temporarily from his role as chief executive of Charles's The Prince's Foundation, while the charity investigates his actions.

A Clarence House spokesman said: "It is right that The Prince's Foundation is taking the investigation so seriously and we will not be commenting further whilst it is ongoing."

The Mail On Sunday published a letter from 2017 in which Mr Fawcett reportedly wrote that he was willing to make an application to change businessman Mahfouz Marei Mubarak bin Mahfouz's honorary CBE to a KBE, and support his application for citizenship.

The letter, written on headed notepaper in Mr Fawcett's then capacity as chief executive of the Dumfries House Trust, said the applications would be made in response to "the most recent and anticipated support" of the Trust.

Mr Mahfouz, who is listed as a supporter on The Prince's Foundation website, is said to have donated large sums to restoration projects of particular interest to Charles. He is said to deny any wrongdoing himself.

Mr Fawcett was Charles's most indispensable aide, with the prince once declaring: "I can manage without just about anyone, except for Michael."

His royal service started in 1981 as a footman to Queen Elizabeth II and he rose through the ranks to become Prince Charles' assistant valet.

He quit as Charles's personal assistant in 2003 after being dubbed "Fawcett the Fence" and accused of selling royal gifts.

He faced allegations of selling unwanted royal gifts and pocketing a percentage of the proceeds, but was cleared by an internal inquiry of any financial misconduct.