Five British police forces have confirmed that phones and tablets seized as evidence have been remotely wiped while in their custody.

Responding to enquiries by the BBC, Cambridgeshire, Derbyshire, Durham and Nottingham police all reported one wiping incident, while Dorset said it had suffered six such incidents in the space of a year. A sixth force, Cleveland, had one wiping case but was uncertain whether this happened before the phone was seized or while it was in custody.

Derbyshire said it had still been able to secure a conviction in the relevant trial, which involved what it described as “romance fraud.” The other forces didn’t comment on whether the wiping had affected their investigations and any subsequent prosecutions.

None of the forces gave specifics on what models of phone or tablet were involved, or what systems and remote wiping facilities they ran.

A digital forensics expert quoted by the BBC suggested police could use a radio-frequency shielded bag to secure seized gadgets from remote wiping. He also noted that as a stop gap measure, devices could be kept inside a microwave oven.

It’s possible that not all of these incidents are cases of a suspected criminal intentionally destroying evidence from afar. It may be that the phone had been stolen and then found on a suspected criminal’s person, with the original phone owner later wiping the phone before discovering the police had it.