A sitting Ukrainian lawmaker who helped Rudy Giuliani smear Joe Biden during the 2020 US presidential campaign has been jailed on suspicion of treason, Ukraine’s State Bureau of Investigation announced Tuesday, in a statement accusing him of carrying out a Russian disinformation operation.

The statement did not name the lawmaker, but a source with the Security Service of Ukraine (SBU) confirmed it was investigating Member of Parliament Oleksandr Dubinsky on suspicion of treason. The statement said the lawmaker “carried out information-subversive activities in favor of the Russian Federation” intended to destabilize and discredit Ukraine.

The SBU has also implicated two former Ukrainian officials in the pro-Russia scheme: ex-lawmaker Andrii Derkach and former prosecutor Kostiantyn Kulyk, who coordinated closely with Giuliani and other allies of former President Donald Trump to peddle false information about Biden and his family’s dealings in Ukraine during the 2020 campaign.

The US government previously sanctioned Dubinsky, Derkach and Kulyk, accusing them of being affiliated with a “Russia-linked foreign influence network” that tried to interfere in the 2020 election in favor of Trump and to undermine Biden. That sanctions announcement came during the final weeks of the Trump administration.

When Giuliani went to Ukraine in 2019 to try to dig up dirt on then-candidate Biden and his son Hunter Biden, Dubinsky was one of the people he met with. Giuliani has also met with Derkach, who was featured prominently in a conspiracy-tinged documentary released by the right-wing network OAN about the Biden family’s dealings in Ukraine.

For his part, Kulyk wrote a dossier of disinformation about the Bidens, including claims about Hunter Biden’s role on the board of Burisma, a major Ukrainian energy company. Kulyk also gave interviews to pro-Trump journalists and hired former Trump lawyers to help him spread his message to US officials during Trump’s first impeachment.

Their activities dovetailed with Trump’s impeachment pushback. Trump embraced their claims, despite concerns that they were working for Moscow. With House Republicans now considering impeaching Biden, some of the GOP claims against him can be traced back to the smears promoted by the three Ukrainian officials now accused of treason.

The SBU said on Telegram that Derkach fled Ukraine on the eve of Russia’s full-scale invasion last year, and that Kulyk is in hiding, outside of the country. Neither has been arrested.

Anti-Biden information operations

Taken together, these developments add to existing allegations that Trump’s inner circle worked with accused Russian operatives to smear Biden, his 2020 opponent. The US and Ukrainian governments have now both said these three Ukrainian officials participated in the Kremlin’s efforts to interfere with the 2020 US election.

The SBU on Monday released a video of testimony from Igor Kolesnikov, a former parliamentary aide who has been convicted of treason, saying that he managed a Russian intelligence operation overseen by the GRU (Russian military intelligence) that included Dubinsky and others aimed at undermining Ukraine’s relations with its allies.

In the video, Kolesnikov says he met a top GRU official in Moscow in 2019 and was directed to “implement a set of information operations as press conferences, six in total, aimed at discrediting the current government, undermining Ukraine’s relations with strategic partners.”

Dubinsky and Derkach later held a series of news conferences that amplified false narratives about corruption by the Biden family in Ukraine. They also promoted the untrue conspiracy theory that Ukraine meddled in the 2016 US presidential election to undermine Trump, contrasting with the reality that Russia meddled to help Trump win.

In his statement released by the SBU, Kolesnikov said he reported back to his Russian handlers after each news conference and they “used their resources to maximize the dissemination of the press conference materials in the media and on the Internet.”

This included translating the news conferences for foreign audiences. And the efforts to spread the material in the US paid off: In August 2020, Trump retweeted a post containing a propaganda audiotape released by Derkach as part of the effort to denigrate Biden.

In a statement on Telegram, Dubinsky denied the allegations and claimed the charges were politically motivated. Dubinsky accused Ukrainian President Volodymyr Zelensky and his chief of staff Andriy Yermak of being responsible for a campaign to silence him.

“I am convinced that Yermak-Zelensky’s chaotic attempts to put me under arrest and ban me from running social networks are connected not only with my criticism of the president and his entourage, but also with the desire to prevent this information from reaching foreign media,” Dubinsky said.

Derkach has previously denied working for the Kremlin. Kulyk has not commented publicly about the allegations.