The security service of Ukraine, or SBU, on Friday searched the home of Nestor Shufrych, a Ukrainian MP from the now-banned, pro-Russian Opposition Platform – For Life party, sources told LIGA.net.

The MP is suspected of high treason and working for former MP and Russian federal security service agent Vladimir Sivkovich, the sources added.

The notorious Mr Sivkovich is believed to have supervised the work of Russian agents in Ukraine, in particular Oleg Kulinich, the former head of the SBU Crimean office, who was detained last year.

"Obviously, on Mr Sivkovich’s instructions, Mr Shufrych was one of the Kremlin’s mouthpieces in Ukraine. For instance, he used to say that our state is an artificial entity," one of the sources told LIGA.net.

In Mr Shufrych's house, SBU officers found Russian military memorabilia, such as St George's ribbons, medals, orders, coats of arms, and military uniforms.

The MP was also found to have certificates of a ‘victory commander’ and a ‘veteran of the Russian armed forces’.

Mr Shufrich still heads the Verkhovna Rada committee on freedom of speech. Last May, he briefly left Ukraine and returned shortly thereafter.