I thought he wasn't even in the UK to be arrested. Did he go back?
Edit:
Brand has not been placed under arrest, the Met tells NPR. The agency says he was interviewed and then charged via "postal requisition" — a court summons informing him of the charges.
https://www.npr.org/2025/04/04/g-s1-58260/russell-brand-rape-assault
I guess the OP thinks he got arrested by mail since that's not even the article title.
He wasn't detained either. He was charged by mail with a summons(postal requisition) and told to show up for his court date in May. In the US an investigative detention means stopping you in one place while in the UK detention generally only means bringing you to the police station and holding you for a charge. In the UK they call the former a stop. You'd have to necessarily be arrested for the later. He didn't have either happen. I don't even think he's in the UK right now(which is likely why they did a postal requisition for a crime as serious as rape without issuing an arrest warrant and starting the extradition process). They want him to come in on his own.
Supposedly they did interview him at one point but that's about it.