Singer Sir Cliff Richard is due to miss this year's Wimbledon - for the first time in 20 years.

The tennis-mad singer will be missing from the tournament, watched by more than 90m TV viewers worldwide, as he prepares for a world-wide tour and continues to battle historic allegations of sexual abuse.

In a significant development this week, the Sunday Mirror has revealed that one of Sir Cliff's accusers has apparently been told by police that they are dropping his case against the 74-year-old pop veteran.

It is understood there are also questions over whether two further accusers' cases will be pursued.

A spokesman for the star said: "Sir Cliff will not be attending Wimbledon this year.

"He has already told the club that he will not be at the championships, but as a tennis fan, and Wimbledon member, he will be watching the tournament on ­television from Portugal while preparing for his forthcoming tour, in respect of which an additional concert in Ireland has just been announced."

Sir Cliff has not been arrested over the claims that first surfaced just weeks after last year’s tournament, which he attended with close friend Cilla Black.

A source close to the star, dubbed the 'Peter Pan of Pop', said: "He is a huge tennis fanatic, and an even bigger fan of Wimbledon.

"He regards it as one of the great British institutions and would be horrified if his presence at Centre Court detracted from the tournament as a tennis event.

"It has been a very difficult time for Sir Cliff but hopefully he will be back in his usual seat next year."

The singer, who plays tennis almost every day, has been a permanent fixture at the fortnight-long event since 1995, famously performing six of his classic hits, including a sing-a-long version of Summer Holiday, egged on by Virginia Wade, when rain delayed play on Centre Court during the 1996 men’s quarter-final.

He also dated former tennis star Sue Barker, now a BBC sports presenter, in the early 1980s.

However, despite the on-going police probe, Sir Cliff is not avoiding the limelight.

On Thursday (June 18) he was at the Theatre Royal in London’s West End to see Hollywood star Bradley Cooper take the lead role in The Elephant Man. He was later a guest at a gala dinner and charity auction.

The source added: "He is certainly not shying away from public life.

"Sir Cliff may spend most of his time abroad but when he is in Britain he is certainly not avoiding public appearances. He still has legions of fans – and continues to hold his head high."

Sir Cliff Richard

One man who accused Sir Cliff of molesting him when he was a youngster has reportedly been told by detectives that no further action will be taken over his allegation.

South Yorkshire Police, which is leading the probe into historic claims against Sir Cliff, refused to comment on Friday (June 19).

Another man had claimed he was abused by the singer when he performed at a huge Christian rally at the city's Bramall Lane football stadium in 1985.

A third man is understood to have contacted police following the original claim.

Sir Cliff, who volunteered to be interviewed under caution by police, vehemently denies all the allegations against him.

Four months ago, South Yorkshire Police Chief Constable David Crompton, in a letter to the chairman of the Commons Home Affairs Select Committee Keith Vaz, said: "This ­investigation has increased significantly in size since its inception.

"Sir Cliff Richard’s lawyers are aware there is more than one allegation."

The February 10 letter went on: "In view of the expanding nature of the investigation it would be premature and potentially misleading to predict a conclusion date.

"We are progressing as swiftly as possible."

Sir Cliff reacted angrily by issuing a statement firmly denying all of the claims.

It read: "I have never, in my life, assaulted anyone. I have no idea where these absurd and untrue allegations come from. I have co-operated fully with the police and I will continue to do so.

"I remain ­confident that the truth will prevail."

Sir Cliff Richard is spotted at Barbados' airport

He added: "Beyond stating that the allegations are completely false, it would not be appropriate for me to say anything further until the ­­investigation has concluded, which I hope will be very soon."

Officers began their probe last August after a man claimed the star attacked him at a rally given by evangelist Billy Graham in 1985.

The search of Sir Cliff's £3.5m home in Sunningdale, Berkshire, was covered live by the BBC, sparking an inquiry into how the corporation knew about the raid.

A report later cleared South Yorkshire Police of seeking publicity but said it should not have released details of the raid which breached the star’s privacy and left him "unnecessarily distressed".

Sir Cliff has spent most of the last 10 months at his whitewashed hillside vineyard retreat in Portugal.

Since 2010 he has split his time between there and his main home, a £6m six-bed villa in Barbados.

Later this year, Sir Cliff is due to begin a major tour marking his 75th birthday. Most of the venues are already sold out.

Over his career he has sold more than 250m records worldwide.

A spokesman for Sir Cliff made no comment on reports police have dropped one case against the singer.