Burisma Holdings used Hunter Biden’s name to lobby for a meeting with U.S. officials shortly before then-Vice President Joe Biden pressured Ukraine into firing its top prosecutor, according to a report.

Ukraine’s then-Prosecutor General Viktor Shokin was at the time overseeing an investigation of the oil and gas giant that employed Hunter Biden on its board of directors.

Breitbart News reported the revelation Monday, citing Obama administration documents obtained by The Hill’s John Solomon though a Freedom of Information Act lawsuit. Solomon said he expects his lawsuit to yield further documents.

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According to Breitbart, the documents released so far show that Burisma representatives in February 2016 sought a meeting with the State Department to discuss allegations of corruption against the company. In their effort to secure the meeting, Burisma representatives invoked the name of Hunter Biden, whom they paid $50,000 to $100,000 to sit on their board.

In March 2016, Joe Biden gave then-Ukrainian President Petro Poroshenko an ultimatum: The government must fire then-Prosecutor General Viktor Shokin or the United States would withhold more than $1 billion of aid to Ukraine. “Look, you’re not getting this money unless Shokin is fired,” Biden told Poroshenko, according to the recollection of Colin Kahl, his longtime national security adviser.

Biden’s pressure campaign against Shokin continued throughout 2016, but was undermined by President Donald Trump’s election victory in November.

Hunter Biden and Burisma: Accusations and counteraccusations

Trump and his allies have alleged that Biden, who is running for the 2020 Democratic presidential nomination, acted to benefit his son.

Joe Biden has denied the accusation, saying he was simply carrying out Obama administration policy in an effort to bolster Ukraine against Russian aggression.

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Hunter Biden has also dismissed the “ridiculous conspiracy idea.” But in the same ABC interview last month, he admitted that Burisma likely hired him because of who his father is, and said he was stepping down from the company’s board.

Meanwhile, House Democrats in September launched an impeachment inquiry over Trump’s efforts to get Ukraine’s new government to investigate Biden’s dealings with the country. Trump has said he did nothing wrong and accused Democrats of waging a partisan campaign to oust him from office.

Solomon, an executive and conservative columnist at The Hill, has come under mounting scrutiny for his reporting on the Bidens.