German skinheads who took home free T-shirts after a music festival on Saturday were in for a big surprise.

The shirts, which bore a skull and crossbones symbol and the word 'Hardcore Rebels,' faded upon washing to reveal a hidden message: "What happened to your shirt can happen to you. We can help you break with right-wing extremism."

The T-shirts were the work of Exit Deutschland, a group that helps young people transition out of militant right-wing lifestyles.

"With these T-shirts we wanted to make ourselves known among right-wingers, especially amongst young ones who are not yet fully committed to the extreme right," said Exit founder Bernd Wagner.

About 250 of the shirts were distributed at the ninth edition of the Rock für Deutschland concert, in the town of Gera, in eastern Germany.

Around 600 neo-Nazis were in attendance at the concert, which is run by the extreme right-wing National Democratic Party.

Author: Sarah Harman (dpa, AFP)

Editor: Martin Kuebler