The Metropolitan Police has decided not to launch a criminal investigation into reports that Andrew Mountbatten-Windsor asked his taxpayer-funded bodyguard to dig up dirt on Virginia Giuffre.
In October The Mail On Sunday claimed the former Duke of York, who is King Charles's brother, passed Ms Giuffre's date of birth and social security number to his close protection officer in 2011 and asked him to investigate as part of a smear campaign against his accuser.
Now Scotland Yard has said the force will not launch an investigation after assessing the claims.
The family of Ms Giuffre have said they are "deeply disappointed" by the force's decision to drop the investigation "without explanation", adding they were not told this announcement was coming.
They said in a statement: "We emailed with a detective from the Metropolitan Police yesterday, Friday, Dec 12th, who gave us no indication that this announcement was imminent.
"Indeed, he asked us if we had any evidence we would like to present; we had not yet replied.
"With the Epstein files about to be released by (the US) congress since the passage of the Epstein Transparency Act, we are surprised that the Metropolitan Police didn't wait to see what further evidence might appear.
"While we have hailed the UK's overall handling of the case of Andrew Mountbatten-Windsor previously, today we feel justice has not been served.
"We continue to challenge the system that protects abusers, especially as more evidence comes to light that can hold people accountable.
"Our sister Virginia, and all survivors, are owed this much."
In a statement announcing the Met would not launch an investigation, Central Specialist Crime Commander Ella Marriott said: "Following recent reporting suggesting that Mr Andrew Mountbatten-Windsor asked his Met Police close protection officer to carry out checks on Ms Giuffre in 2011, the MPS (Metropolitan Police Service) has carried out a further assessment.
"This assessment has not revealed any additional evidence of criminal acts or misconduct.
"The Met remains committed to thoroughly assessing any new information that could assist in this matter.
"To date, we have not received any additional evidence that would support reopening the investigation.
"In the absence of any further information, we will be taking no further action.
"As with any other matter, should new and relevant information be brought to our attention, including in any information resulting from the release of material in the US, we will assess it."
Andrew has long made headlines over his association with Epstein, with Charles officially stripping his disgraced brother of both his HRH style and his prince title in recent months.
The former duke has for many years faced allegations that he sexually assaulted a teenage Ms Giuffre after she was trafficked by Epstein.
Andrew strenuously denies the accusations.
He paid millions to Ms Giuffre to settle a civil sexual assault claim in 2022.
Andrew stepped down from royal duties in 2019 after his disastrous Newsnight interview but the publication of Ms Giuffre's posthumous memoirs, and the US government's release of documents from Epstein's estate, has brought fresh focus on Andrew recently.
In October The Mail On Sunday reported that Andrew embarked on a bid to smear Ms Giuffre.
He is said to have emailed the late Queen's then-deputy press secretary and told him of his request to his protection officer, and also suggested Ms Giuffre had a criminal record.
Andrew's alleged attempt, on which the police officer is not said to have acted, came in 2011, hours before the newspaper first published the famous photograph of Andrew with his arm around Ms Giuffre in London.
The newspaper said it obtained the email from disclosures held by the US congress.
