Several Muslim terrorists in Europe have been caught with child pornography in their computers, and investigators now suspect that the images are being used by terrorist networks to pass messages, according to the British Sunday Times. Unusually graphic child pornography has been found in anti-terror investigations in Britain, Italy, and Spain, the paper said.

Terrorists are encoding images and videos with secret messages, which can be detected using special applications, according to the Times. An average observer would be unable to detect the message, and even police might find it difficult to decipher due to advances in encryption technology.