In 1983 he smuggled an open letter from prison in Siberia to the Madrid Conference on Security and Cooperation in Europe, calling for the Soviet Union to stand by the humanitarianism clauses of the Helsinki Agreement - for which he was put into solitary confinement.

[3] He spent four years in political prison camps VS-389/37 and VS-389/36 in the Perm region, and then settled in East Yakutia (Kolyma).

He contributed to Radio Free Europe and participated in the activities of the Estonian Imprisoned Freedom Fighters Assistance Center.

He was sentenced to one year's suspended imprisonment with a two-year probation period and compensation for financial damage (210,280 kroons) to the company.

[5] In 1996, the court convicted Madisson "of being dissatisfied with the situation in Estonia in May 1996, as a member of the Defence League, to prepare for a military coup" and "sought accomplices to implement his plans and ideas".