President Donald Trump‘s personal attorney, Rudy Giuliani, has been meeting with Ukrainians for a documentary series trying to discredit the ongoing impeachment effort.

Giuliani met with Ukraine’s former prosecutor general Yuriy Lutsenko in Budapest on Tuesday. He traveled to Kyiv the next day and tried to meet with other former Ukrainian prosecutors, including Viktor Shokin and Kostiantyn Kulyk.

The three former Ukrainian officials have all been name-dropped in the impeachment inquiry.

The inquiry centers around Trump’s attempts to pressure the Ukrainian government to launch a political probe into former Vice President Joe Biden. Trump asserted that Biden forced the firing of Shokin because he had been investigating Burisma Holdings, a Ukraine-based natural gas company that his son worked for.

Although Biden did pressure the government to fire Shokin, there is no evidence to suggest that he was acting in the business interests of his son. Various US officials had publicly criticized Shokin for being corrupt, including Victoria Nuland, the assistant secretary of state for European and Eurasian affairs.

Nuland said in October 2015 that the prosecutor’s office had to be “reinvented as an institution that serves the citizens of Ukraine, rather than ripping them off.”

Kulyk was recently fired by the new prosecutor general as part of an anti-corruption initiative. Kulyk accused Biden’s son, Hunter, of corruption and tried to open an investigation into Burisma.

Lutsenko gave information about the Bidens to Giuliani and largely helped circulate the conspiracy theory of Biden family corruption. His information likely caused Trump to ask the Ukrainian president during a July 25 phone call to look into Burisma and Biden.

Lutsenko has since said that the Biden family did not violate any laws in Ukraine.

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Giuliani was accompanied to Europe by a film crew from the conservative cable channel, One America News. The reporter who hosts the series, Chanel Rion, was also in Budapest for an interview with Lutsenko.

Giuliani defended his conversations with the Ukrainian lawyers, telling the New York Times that “like a good lawyer, I am gathering evidence to defend my client against the false charges being leveled against him.”