"The SBU has opened a criminal case against the former president of Ukraine and judges of the Constitutional Court based on Part 2 of Article 364 (abuse of power)," Gytlianska said.

"The criminal case concerns the usurpation of power, in particular, with respect to illegal amendments to the Constitution [made] in 2010.

"More information will be made available during the day," Gytlianska added.

Earlier, Karl Volokh, a member of the Public Council under the Ministry of Justice, said proceedings against Yanukovych and the court judges were likely to go ahead.