The police investigation into Andrew Mountbatten-Windsor will assess claims of sexual misconduct.
The former Duke of York was arrested at his home on the Sandringham Estate in February on suspicion of committing misconduct in a public office.
As part of its investigation, it is understood Thames Valley Police (TVP) will review allegations of sexual misconduct.
Detectives are investigating claims Mountbatten-Windsor, 66, passed sensitive information to Jeffrey Epstein when the then prince was working as a UK trade envoy.
As special representative for trade and investment, Mountbatten-Windsor was granted access to senior government and business contacts around the world.
The Epstein files appeared to show that he forwarded official reports to the paedophile about trips to Hong Kong, Singapore, Vietnam and China in November 2010.
However, an individual can also be guilty of misconduct in a public office if they use their position to instigate “sexual or inappropriate relationships”, according to Crown Prosecution Service (CPS) guidelines.
Prosecutors must then prove the alleged misconduct amounted to a “wilful abuse of power”.
The police are also understood to be considering investigating potential corruption and fraud offences that could constitute misconduct in public office.
Police ‘committed to thorough investigation’
Assistant Chief Constable Oliver Wright said: “Misconduct in public office is a crime that can take different forms, making this a complex investigation.
“Our team of very experienced detectives are working meticulously through a significant amount of information that has come in from the public and other sources.
“We are committed to conducting a thorough investigation into all reasonable lines of inquiry, wherever they may lead.
“We encourage anyone with information to get in touch with us through the normal non-urgent contact channels, such as the Thames Valley Police online portal.
“I understand the high level of interest in this work, but please be patient as we continue to actively progress our investigation.”
TVP is currently assessing one allegation that a woman was trafficked into Britain by Epstein in 2010 to have sex with Mountbatten-Windsor at Royal Lodge in Windsor.
The force has been in contact with the woman’s legal team.
TVP also urged any women who were abused by Epstein to contact officers if they had information that would assist their investigation.
Wright said: “We’ve been working really closely with the Department of Justice in the United States seeking further information that may be related to this investigation.
“We’re encouraging anyone with information to get in touch with us.
“In terms of Epstein victims and survivors, we hope that anyone with relevant information will come forward, and I really want to stress that our door is open.”
A national gold group hosted by the National Police Chiefs’ Council is co-ordinating British police efforts to investigate allegations revealed in the Epstein files.
Mountbatten-Windsor was arrested on his 66th birthday at Wood Farm in the Sandringham Estate on February 19.
He was released under investigation after spending more than 12 hours in police custody. He denies any wrongdoing.
The property was searched, as was his former home at Royal Lodge.
It is understood detectives recovered potential evidence from the properties, which they are currently examining.
A dedicated team of specialist officers is working closely with the Government, the Cabinet Office and the Royal Household. The latest update on the investigation comes as a trove of documents related to Mountbatten-Windsor’s appointment as trade envoy were published.
The files contain a memo stating that Elizabeth II was “very keen” for Mountbatten-Windsor to take on a “prominent role in the promotion of national interests”.
The release of the files today came after the Liberal Democrats tabled a humble address in Parliament calling for the publication of papers on Mountbatten-Windsor’s role, including any vetting and any correspondence from Lord Mandelson.