Originally Posted by Cathar
I assume that this is an AAIB accident inspector from what has been said in the news report. Inspectors have various powers under the Civil Aviation (Investigation of Air Accidents and Incidents) Regulations 1996. The Regulations can be found
here
The AAIB can also order the Responsible Person or a Constable to impound anything that they think they might need (such as FDRs, CVRs - or presumably whole aircraft) for an investigation, before they can arrive on the scene themselves. The Police can also detain anyone that they think might have carried out a criminal act, such as a breach of the Air Navigation Order.
TheOddOne