Ukraine is finishing the preparation of the fourth lawsuit filed with European Court of Human Rights (ECHR) against Russia, Ukrainian Justice Minister Pavlo Petrenko has said.

"I'd like to announce the filing of the fourth international lawsuit against Russia with the ECHR by Ukraine," he said at a press conference in Kyiv on Tuesday.

According to him, documents on the lawsuit will be finished next week.

It will concern the violation of human rights in annexed Crimea, in particular on the political motives behind the persecution of Ukrainian on the peninsula.

"I am speaking about violations that have been registered after the previous three complaints were submitted. These breaches mainly include the politically motivated persecution of the Ukrainians, the Crimean Tatars and other indigenous ethnic groups by the occupation authorities in the territory of Crimea, the minister said.

The second group of rights violations includes violations of the right to free elections, he said.

"Hundreds of thousands of Ukrainians living on the territory of occupied Crimea were unable to take part in the last parliamentary election campaign and cast their ballots," Petrenko said.