The Czech Supreme Court has canceled a 1973 sentence by a communist court that gave four people prison terms for singing an anti-Soviet, anti-communist song in a Prague pub.

A retired major of the communist secret police heard the four singing the song July 28 that year and called the police. They were convicted of hooliganism and sentenced to up to one year behind bars.

Supreme Court spokeswoman Dana Haisova said Wednesday the court canceled the sentences because they were not appropriate and the four, who all went to prison, could now seek compensation from the Justice Ministry.

Ivan Martin Jirous, a poet and artistic leader of the Plastic People of the Universe, a nonconformist rock band banned by the communist regime, was among the four.