Rudy Giuliani confessed on Wednesday to discussing a theory about Ukraine and the 2016 election with President Donald Trumps convicted former campaign chairman Paul Manafort. 

Giuliani, Trump’s personal lawyer, told The Washington Post that he reached out to Manafort to consult him on an unverified claim that Ukraine meddled in the 2016 election to help Hillary Clinton. The former New York City mayor previously admitted to believing this theory in an interview with CNN’s Chris Cuomo last month. During that interview, Giuliani also contradicted himself about his involvement in Trump’s effort to pressure Ukraine’s president to investigate Joe Biden and his son.

This week, House Democrats subpoenaed Giuliani for documents related to Trump’s call with Ukrainian President Volodymyr Zelensky on July 25 as part of their impeachment inquiry sparked by a whistleblower’s complaint.

Giuliani also told The Post that he hasn’t spoken to Manafort in two years but felt it was necessary to reach out to the former lawyer and political consultant. In March, Manafort was sentenced to a combined 7.5 years in prison for multiple charges, including bank and tax fraud, related to his work as a lobbyist for pro-Russian political candidates and parties in Ukraine. The New York Times also reported Manafort’s ties to former Ukrainian President Viktor Yanukovych in 2016. According to the newspaper, Manafort took $12.7 million in undisclosed payments from Yanukovych’s party from 2007 to 2012.

Giulani said he was seeking to “prove” that a black book that allegedly contained details of the undisclosed payments to Manafort did not exist. Giuliani said he believed this ledger was simply an excuse for investigators to reopen their case against Manafort.

“‘Was there really a black book? If there wasn’t, I really need to know. Please tell him I’ve got to know,'” Giuliani told the newspaper he asked Manafort’s attorney. “He came back and said there wasn’t a black book.”