As Donald Trump began his meteoric rise to the presidency, the Obama White House summoned Ukrainian authorities to Washington to coordinate ongoing anti-corruption efforts inside Russia’s most critical neighbor.

The January 2016 gathering brought some of Ukraine’s top corruption prosecutors and investigators face to face with members of former President Obama’s National Security Council (NSC), FBI, State Department and Department of Justice (DOJ).

The agenda suggested the purpose was training and coordination. But Ukrainian participants said it didn’t take long — during the meetings and afterward — to realize the Americans’ objectives included two politically hot investigations: one that touched Vice President Joe Biden’s family and one that involved a lobbying firm linked closely to then-candidate Trump.

U.S. officials “kept talking about how important it was that all of our anti-corruption efforts be united,” said Andrii Telizhenko, then a political officer in the Ukrainian Embassy in Washington tasked with organizing the meeting .Telizhenko said U.S. officials volunteered during the meetings that they had an interest in reviving a closed investigation into payments to U.S. figures from Ukraine’s Russia-backed Party of Regions.

That 2014 investigation was led by the FBI and focused heavily on GOP lobbyist Paul Manafort

Nazar Kholodnytskyy, Ukraine’s chief anti-corruption prosecutor, said he soon saw evidence in Ukraine of political meddling in the U.S. election. Kholodnytskyy said the key evidence against Manafort — a ledger showing payments from the Party of Regions — was known to Ukrainian authorities since 2014 but was suddenly released in May 2016 by the U.S.-friendly NABU, after Manafort was named Trump’s campaign chairman:

“Somebody kept this black ledger secret for two years and then showed it to the public and the U.S. media. It was extremely suspicious.”

Kholodnytskyy said he explicitly instructed NABU investigators who were working with American authorities not to share the ledger with the media.

“Look, Manafort’s case is one of the cases that hurt me a lot,” he said.“I ordered the detectives to give nothing to the mass media considering this case. Instead, they had broken my order and published themselves these one or two pages of this black ledger regarding Paul Manafort."