AceShowbiz - Police in Germany have launched an investigation into claims two computer hackers stole unreleased songs from stars including Justin Timberlake, Lady GaGa, Rihanna and Ke$ha and leaked them online. The men, aged 17 and 23, are alleged to be part of a network of cyber-crooks who deliberately targeted laptops linked to some of the world's biggest pop stars before downloading personal data, including new tracks.

They then either uploaded the songs to the internet or tried selling them for thousands of Euros, according to investigators. Some of the famous victims - also believed to include Kelly Clarkson - are said to have rush-released their new album and headed out on tour early as a result of the leaks.

It is also alleged that during the hacking - achieved by targeting computers with a Trojan horse virus - the two men discovered an intimate photograph which was then used to blackmail "TiK ToK" hitmaker Ke$ha. The suspects, from the German cities of Duisburg and Wesel, are under investigation but have not yet been charged with any offense.

State prosecutor Rolf Haferkamp says, "We are talking about illegal bootlegged publication and spying on data using Trojans... The trick itself is nothing special. All it requires is a bit of know-how and perseverance to achieve criminal success."

Universal Music's Senior Director of Promotion, Publicity & PR in Germany, Sven Kilthau-Lander - who handles publicity for artists including GaGa and Rihanna - tells WENN, "It's really frightening. One can't feel safe anywhere." The hacking scandal is said to have been exposed after suspicious fans of Clarkson alerted her fan club to the leaked tracks.