Someone from the Home Office said my BRP is under investigation and asked for money, is this fraud?

The Home Office or the police will never ask for a money transaction if there is an error with your BRP. In most cases, this will be up to you to identify and correct, rather than them contacting you. If this has happened to you, please report this to Action Fraud if you are in the UK or by phoning their helpline on 0300 123 2040. You can find more information on the Home Office webpages as to how fraudsters may contact you.