Minsk/Moscow  - Belarussian opposition politician Aleksander Konsulin has been surprisingly released from prison, his daughter disclosed Saturday.

An Interfax agency report from Minsk gave no reason behind the early release of Konsulin, who in March 2006 was sentenced to a five and one-half year prison term for "serious rowdyism" and for organising an unauthorised public gathering.

Konsulin, a former presidential candidate, has been one of the stiffest critics of the authoritarian rule of President Aleksander Lukashenko.

The European Union had set the release of Konsulin and other opposition politicians as a condition for a revival of relations between Brussels and Minski.

The release of Konsulin comes as Belarus prepares for its next parliamentary elections, on September 28. (dpa)