UKRAINE has placed the leader of its biggest opposition party under house arrest on charges that he says are politically motivated.

Viktor Medvedchuk heads the Opposition Platform – for Life party, a left-leaning organisation that attracted Kiev’s ire recently for staging anti-fascist marches on Victory Day (May 9, the date of the 1945 Nazi surrender to the Soviet Union).

Mr Medvedchuk is accused of disclosing state secrets on the deployment of military units to Russia and of transferring oil and gas production licences in Crimea to its authorities. The peninsula, where ethnic Russians comprise the majority of the population, was occupied by Russia following the Maidan coup in Ukraine in 2014, and voted to reunite with Russia (of which it was a part until 1961) shortly afterwards.

The Ukrainian opposition leader is personally close to Russian President Vladimir Putin, who is godfather to his daughter. However, he rejects the allegations and says that they form part of a wider crackdown on opposition voices. Three TV channels – 112, Zik and NewsOne – have been shut down so far this year, accused of promoting pro-Russian propaganda.

Opposition – For Life is one of a sequence of short-lived parties considered a successor to ousted president Viktor Yanukovych’s Party of the Regions, which was banned after his overthrow. Like the Party of the Regions, it is strongest in Ukraine’s Russian-speaking east.

One of its MPs, Oleh Voloshyn, urged Western governments recently to call out Ukraine on its tacit support for fascist and neonazi organisations following a march in honour of the SS Galicia division in Kiev last month.