A woman unwittingly took her own picture as she unlocked a stolen iPhone - only for the image to be sent to the owner who then called police.
An app downloaded on to the phone takes a picture of anyone who tries to unlock it, maps their location and then sends the information to the owner in an email, Sussex Police said.
The phone was stolen from the Coalition nightclub in Brighton, East Sussex, earlier this month.
Police said they do not know whether the woman pictured was responsible for the theft but they appealed for her or anyone who recognises her to contact them.
Pc Gavin Crute, of Sussex Police, said: "The owner of the camera has a rather cool app that takes a picture of anyone who tries to unlock it, maps their current location and then sends all the info back to the owner in an email.
"We know where and when the photo was taken and it appears to be in a vehicle with quite a large sunroof.
"We don't know that the woman is the person who stole the camera, but she obviously has had some connection with it in the meantime and I'd like to speak to her about it."
Anyone with information is asked to call Sussex Police on 101.