He was among the four leaders (the Ilie Ilașcu group, comprising also Alexandru Leșco and Tudor Petrov Popa) of the Tiraspol branch of the pro-Romanian Christian-Democratic People's Party of Moldova who were accused of terrorism by the authorities of the breakaway Pridnestrovian Moldavian Republic (PMR).
Ivanțoc was arrested on 2 June 1992, and sentenced to 15 years of prison in a trial, which the European Court of Human Rights considered to be unfairly conducted by the PMR authorities.
On 9 December 1993, the Supreme Court of the PMR found Ivanțoc guilty of murdering a representative of the State with the aim of spreading terror, unauthorised use and theft of ammunition or explosives, and assault.
[4] Ivanțoc became a Romanian citizen in 2001 while in prison, and in March 2005, he was proposed by the Social Liberal Party as a candidate for the position of President of Moldova.
On 27 February 2006, he started a hunger strike in protest against the "abusive, inhuman and degrading treatment" he was receiving from the PMR authorities.