Andrew Mountbatten-Windsor has been arrested on suspicion of misconduct in public office - but what is the offence?
Misconduct in public office refers to "serious wilful abuse or neglect" of powers relating to the role in public office, according to the Crown Prosecution Service (CPS).
It states there must be a direct link between the misconduct and an abuse of those powers or responsibilities without reasonable excuse or justification.
Andrew has consistently denied any wrongdoing.
Follow live updates
Joshua Rozenberg, a legal commentator, told Sky News that it is an "unusual" offence "because it's one created by the judges, laid down by the courts over many years" instead of statute.
He said: "For that reason, there isn't actually a maximum penalty at all. It's life imprisonment because parliament has never actually set a maximum.
"What it actually boils down to is whether the police have evidence that Andrew Mountbatten-Windsor wilfully misconducted himself as a trade envoy to such a degree as to amount to an abuse of the public's trust in him."
The CPS website states there is no simple definition of a 'public officer', meaning each case must be assessed individually.
This includes taking into account the nature of the role, the duties carried out, and the level of public trust involved.
The British Monarchy acts as a public institution in a non-political sense, with members of the Royal Family expected to support the monarch while also carrying out work in the areas of public and charitable service in their own right.
Due to the "complicated" nature of the offence, Mr Rozenberg said the government is trying to replace it with a new law, the Public Office (Accountability) Bill, which is currently going through parliament.
Part of the bill covers misconduct in public office, stating that a person commits an offence if they use "their office to obtain a benefit, whether for themselves or somebody else, or to cause somebody else to suffer a detriment".
How long can police hold Andrew?
It remains unknown where Andrew is being held, or what time he was arrested, but suspects are typically held for 24 hours and are then either charged or released pending further investigation.
Technically the longest the former prince can be held by police is 96 hours, however this would require several extensions from senior police officers and a Magistrates' Court.
For an extension to be applied, the court must be satisfied that the detention is necessary to secure/preserve evidence, the investigation is being conducted diligently, and the offence is serious.
Mr Rozenberg told Sky News that he thought it was unlikely Andrew would be held overnight, if he is being questioned at a police station.
"That's perhaps one reason for arresting him first thing in the morning," he said.
"But again, if he doesn't have anything to say, and I'd be surprised if he wants to say anything to the police, then perhaps the interview isn't going to take very long."
(c) Sky News 2026: What is misconduct in public office?
Andrew Mountbatten-Windsor arrest 'worst possible thing' for the Crown, Sky's royal commentator says
British couple's 10 year Iran prison sentence has left them in 'panic', says son
Gorton and Denton by-election: It's the UK's first crucial vote of the year - and something striking seems to be happening
Drug dealer jailed for life over arson attack on St Helens home that killed elderly couple
How US military is assembling within striking distance of Iran
Number of norovirus patients in England at highest level this winter, as NHS warns of 'second surge'
Pupils with SEND to have support reviewed when they join secondary school
Bill Gates withdraws from Indian AI Impact Summit