Andrew Mountbatten-Windsor has been arrested on suspicion of misconduct in public office.
The former prince was detained at Wood Farm on the Sandringham Estate on Thursday morning.
He has not been charged and has previously denied wrongdoing.
Misconduct in public office is a common law offence triable in the Crown Court and carries a maximum sentence of life imprisonment.
Legal proceedings are now active, and police have warned against commentary that may prejudice the ongoing investigation.
The offence of misconduct in public office was described by legal scholar Sir William Blackstone in 1765 as “a crime of deep malignity”.
In most cases, a significant prison sentence is imposed on a convicted offender – and there are around 25 to 50 convictions each year.
Allan Maidment, Head of Regulatory at MSB Solicitors, said: “Misconduct in public office is a common law offence triable only in the Crown Court and, upon conviction, carries a maximum sentence of life imprisonment.
“Allegations of this nature are serious and are likely to involve a complex and detailed criminal investigation. If charges were ultimately brought, proceedings could take a significant period of time to progress through the Crown Court due to the evidential and legal issues often involved.
“The offence centres on the alleged wilful abuse of power by someone holding a public office. It is important to note that misconduct in public office is a distinct legal offence and does not, by itself, encompass allegations of sexual offending.
“At this stage it would be speculative to comment on the specific circumstances that led to the suspicion of misconduct or the arrest, and any next steps will depend on the outcome of the ongoing investigation.”
Legal proceedings became active at the time of Andrew’s arrest. Police have warned people not to share or post anything that may prejudice the ongoing investigation, including on social media.
