Scientists have discovered a way to use infrared cameras to seek out tattoos that people have had covered up or changed.

Often used as a distinguishing factor to identify criminals, tattoos can be altered or removed relatively easily, but a team at the University of Derby has come up with a solution.

Using infrared means that removed tattoos, or even tattoos that have been altered, can be spotted in the deeper layers of skin.

Infrared filter

"Identifying individuals using tattoos has been an established part of forensic science practice for some time, but there can be cover-ups of tattoos with lasers, more tattoos or surgery," said David Bryson – senior lecturer in applied photography and forensic science at the University of Derby.

"It is now possible to take a control photograph and a separate photograph with an infrared filter to take images of the tattoo, and determine if it is indeed the original or is a cover-up, or altered tattoo on the surface."