Criticism has grown over the handling of the investigation into allegations facing Sir Cliff Richard.

Police raided his home in Sunningdale, Berkshire last week, when he was on holiday in Portugal, in connection with an alleged historic sex offence.

According to the BBC, the alleged offence took place at a Billy Graham event in Sheffield in 1985, at which Sir Cliff was speaking.

It emerged over the weekend that a BBC reporter had approached South Yorkshire police with the story weeks before the raid took place.

The police gave the BBC information ahead of the raid, and a BBC film crew and helicopters were present as it happened.

In a statement issued on Saturday, South Yorkshire police said: "Contrary to media reports, this decision [to inform the BBC ahead of time] was not taken in order to maximise publicity, it was taken to preserve any potential evidence."

Writing in the Independent, Geoffrey Robertson QC said that police had subverted due process by waiting until Sir Cliff was on holiday, and accused them of "orchestrating massive publicity for the raid on his house, before making any request for interview and before any question could arise of arresting or charging him".

"[the] police from Thames Valley and South Yorkshire, aided and abetted by the BBC and a Sheffield lay justice, have blasted his reputation around the world without giving him the first and most basic right to refute the allegation,' he wrote.

The former Attorney General Dominic Grieve, said the police's handling of the case was 'odd' and 'very questionable'.

"I can see that police might not want to warn somebody about a search because they fear a suspect will destroy the evidence. But it was much odder to tip off the BBC that they were carrying out the raid. That seems quite extraordinary. I have no reason to think they are acting capriciously but I think it was odd to notify the BBC so they could have journalists there to film the events."

"Unless the police can show the sound public reason for doing that it suggests a collusive relationship with the BBC which is very odd.

"The BBC's presence is not required. The police have not arrested him or charged him. All they have done is carry out a search of his house so why have they notified the BBC so it could film this operation taking place? I simply don't understand it. It is very questionable."

Sir Cliff said in a statement: "For many months I have been aware of allegations against me of historic impropriety which have been circulating online.

"The allegations are completely false. Up until now I have chosen not to dignify the false allegations with a response, as it would just give them more oxygen."