The investigation into sex abuse claims against Sir Cliff Richard cost £800,000.
South Yorkshire Police today revealed that the initial claim, that the singer abused a teenage boy at an event in Sheffield in 1985, led to eight further allegations being made.
Police files on four of the allegations were considered by the Crown Prosecution Service but today it was announced that no action is to be taken due to a lack of evidence.
Detectives investigated five other claims but did not refer them to the CPS.
Officers from South Yorkshire Police raided Sir Cliff's Berkshire home as part of the probe into the initial sex abuse claim, with BBC cameras televising the police action.
Then Chief Constable David Crompton was criticised by MPs for details of the pre-planned raid being leaked to journalists.
A South Yorkshire Police spokeswoman said: "In May this year, South Yorkshire Police presented the final investigation files to the Crown Prosecution Service relating to four allegations of non-recent sexual abuse involving a 75-year-old man.
"After careful consideration of the evidence provided to them, the CPS has concluded that no further action should be taken against the man due to there being insufficient evidence to prosecute. A further five allegations considered by the investigation team did not meet the threshold for referral to CPS for a charging decision.
"South Yorkshire Police accept the decision of the CPS in this case and all those involved have been informed.
"The force apologises wholeheartedly for the additional anxiety caused by our initial handling of the media interest in this case and has implemented the learning from this and the subsequent review conducted by former Chief Constable Andy Trotter.
"Following an initial allegation received by the force in April 2014, South Yorkshire detectives have explored and gathered all information available and carried out a thorough and detailed investigation, which has covered the UK and abroad.
"The investigation, which has spanned two years, is estimated to have cost in the region of £800,000, including staffing costs.
"Non-recent allegations are, by their very nature, complex and difficult matters to investigate and can take a considerable amount of time.
"We appreciate that waiting for a conclusion will undoubtedly have caused additional distress to all those involved and we have made every effort to ensure this has been as timely as possible. However, it is in the interests of justice to investigate such matters thoroughly. We have a duty to explore any allegations relating to sexual abuse and other crimes and will go wherever the evidence takes us in order to protect victims and stop offending.
"We encourage victims of non-recent abuse to have the confidence to come forward, knowing they will be listened to and that their allegations will be taken seriously and investigated. It is also important for those under investigation to know they will be treated fairly.
"Whilst recognising how difficult it is for a person to be under investigation and have their innocence publically called into question, South Yorkshire Police acknowledges and takes seriously its responsibility to fully investigate allegations of non-recent abuse."
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