"Investigators of the Security Service of Ukraine opened criminal proceedings on the fact of illegal elections to the State Duma of Russia, which took place the other day on the territory of the temporarily occupied Crimea," the website says.
As noted, the case was opened under the article on high treason.
Earlier, Secretary of the Ukrainian National Security and Defense Council (NSDC) Oleksiy Danilov announced sanctions against persons involved in organizing elections in Crimea.
Crimean Senator Olga Kovitidi commented on this statement in an interview with RT.
Crimea became a Russian region following a March 2014 referendum in which most of the peninsula's residents voted for reunification with Russia.