Ukrainian police and prosecutors have accused two politicians and a former prosecutor of treason, saying they colluded with a Russian intelligence agency in aiding an effort by Rudolph W. Giuliani several years ago to tie the Biden family to corruption in Ukraine.
Those accused include Kostyantyn Kulyk, a former Ukrainian deputy prosecutor general who had drafted a memo in 2019 suggesting Ukraine investigate Hunter Biden, President Biden’s son, for his role serving on the board of a Ukrainian energy company.
Also implicated were a current member of Ukraine’s Parliament, Oleksandr Dubinsky, and a former member, Andriy Derkach, who had publicly advocated for an investigation in Ukraine into Hunter Biden. They had also promoted a spurious theory that it was Ukraine, and not Russia, that had meddled in the 2016 presidential election in the United States.
The three were indicted on charges of treason and belonging to a criminal organization. The charges refer to “information-subversive activities” and focus on actions in 2019 before the American presidential election. They do not say if or when the activity stopped.
In the run-up to the 2020 election in the United States, Mr. Giuliani and later former President Donald J. Trump had encouraged Ukrainian officials to follow up on the allegations against Hunter Biden. The effort included a phone call by Mr. Trump to President Volodymyr Zelensky in July of 2019 urging an investigation into the Bidens, at a time when the Trump administration was withholding military aid for the Ukrainian Army.
Critics say that pressure to investigate the Bidens was politically motivated, aimed at harming the elder Mr. Biden’s chances against Mr. Trump in the 2020 presidential election.
Mr. Trump and Mr. Giuliani denied that there was anything inappropriate about their contact with Ukrainian officials, with Mr. Trump describing his phone call to Mr. Zelensky as “perfect.” The administration said military aid to Ukraine was withheld over concerns about corruption in the Ukrainian government.
The events led to Mr. Trump’s first impeachment in the House of Representatives. He was acquitted in the Senate.
Ukrainian media on Tuesday suggested the indictments, too, had a political component for Mr. Zelensky: that they were intended to send a signal to Mr. Biden now, as his administration is pressing Congress for military assistance to Ukraine, that Kyiv will root out accused Russian agents, including those who had promoted accusations against his family.
In statements released on Monday, Ukrainian police and the country’s domestic intelligence agency said all three men were members of a spy network established inside the Ukrainian government and handled by Russia’s military intelligence agency, known as the G.R.U.
The intelligence agency’s statement said the Russians paid members of the group $10 million. An aide to Mr. Derkach, Ihor Kolesnikov, was detained earlier and convicted on treason charges.
Two members of the group, Mr. Derkach and Mr. Kulyk, fled Ukraine after Russia’s full-scale invasion in 2022, the statement said. Mr. Dubinsky was remanded to pretrial detention in a Ukrainian jail on Tuesday.
Mr. Dubinsky, in a statement posted on the social networking site Telegram, said that the prosecutors had “not presented one fact” to support the accusations, and that the charges were retribution for criticizing Mr. Zelensky’s government in his role as a member of Parliament. He said that he testified a year and a half ago as a witness in a treason investigation of Mr. Derkach but at the time had not been accused of any wrongdoing.
Mr. Dubinsky was expelled from Mr. Zelensky’s political party, Servant of the People, in 2021 after the United States sanctioned him for meddling in the American political process.
The Ukrainian intelligence agency’s statement said that Mr. Kulyk had used his position in the prosecutor general’s office to promote investigations that worked “in favor of the Kremlin,” without specifying any cases.
In late 2018, Mr. Kulyk compiled a seven-page dossier asserting that Ukrainian prosecutors had evidence that “may attest to the commission of corrupt actions aimed at personal unlawful enrichment by former Vice President of the United States Joe Biden,” according to a copy leaked by a Ukrainian blogger.
The dossier suggested that Mr. Biden, when he had served as vice president, had tried to quash a corruption investigation into the natural gas company, Burisma Holdings, where his son served on the board. Former colleagues of Mr. Kulyk at the prosecutor’s office confirmed he had written the document, which helped set in motion an effort by Mr. Trump’s personal lawyer, Mr. Giuliani, and other supporters to press for an investigation in Ukraine.
In a phone call with Mr. Zelensky that became central to the impeachment case, Mr. Trump had asked the Ukrainian president to investigate supposed conflicts of interest by Mr. Biden when he was vice president, according to White House notes of the call. Mr. Trump denied he had linked military aid to Ukraine to the investigation of the Biden family.
Allegations of corruption and ties to Russia had trailed Mr. Kulyk for years in the Ukrainian media and among anti-corruption watchdog groups before he compiled the dossier.
In 2016, he was indicted in Ukraine on charges of illegal enrichment for owning apartments and cars that seemed beyond the means of his modest official salary. One car, a Toyota Land Cruiser, had been bought by the father of a military commander fighting on the Russian side in the war in eastern Ukraine.