Last March, a veteran Washington reporter taped an interview with a Ukrainian prosecutor that sparked a disinformation campaign alleging Joe Biden pressured Ukrainians into removing a prosecutor investigating a company because of its ties to the former vice president’s son. The interview and subsequent columns, conducted and written by a writer for The Hill newspaper, John Solomon, were the starting gun that eventually set off the impeachment inquiry into the president.

Watching from the control booth of The Hill’s TV studio was Lev Parnas, who helped arrange the interview.

Parnas and his partner Igor Fruman were working with the president’s personal lawyer, Rudy Giuliani, to promote a story that it was Democrats and not Republicans who colluded with a foreign power in the 2016 election. Federal prosecutors in Manhattan indicted the duo this month on allegations that they illegally funneled foreign money into U.S. political campaigns.

Interviews and company records obtained by ProPublica show Parnas worked closely with Solomon to facilitate his reporting, including helping with translation and interviews. Solomon also shared files he obtained related to the Biden allegations with Parnas, according to a person familiar with the exchange. And the two men shared yet another only recently revealed connection: Solomon’s personal lawyers connected the journalist to Parnas and later hired the Florida businessman as a translator in their representation of a Ukrainian oligarch.

Solomon’s interview and columns were widely amplified. Giuliani praised them, and Trump said he deserved a Pulitzer Prize. Fox News hosts Sean Hannity, Laura Ingraham and Lou Dobbs trumpeted them. They later become a key point in the CIA whistleblower complaint that set the impeachment inquiry in motion.

Parnas’ unusual and extensive involvement in the production of the stories has not been previously reported.

Solomon, 52, told ProPublica his reporting was accurate and defended his sourcing, saying, “No one knew there was anything wrong with Lev Parnas at the time.”

“Everybody who approaches me has an angle,” he said. “My mother has an angle when she calls me.” A lawyer for Parnas, who along with Fruman has pleaded not guilty, didn’t return requests for comment.

More than a year before his Ukraine columns published, The Hill had serious concerns about Solomon’s credibility and conflicts of interest. Hill staffers began raising alarms, including the paper’s publisher at the time, who warned in an internal memo that Solomon was engaged in “reputation killing stuff” by mixing business with journalism.

In response, The Hill’s management took steps to limit Solomon’s reporting — rebranding him as an opinion writer — but did not prevent him from writing his Ukraine series.

“Nothing I did would have put The Hill’s reputation at risk,” Solomon said.

Solomon came to The Hill, which specializes in inside-the-Beltway news, in July 2017 after a decades long career that included stretches at The Associated Press, The Washington Post and The Washington Times. His work has earned accolades, including a series examining what the FBI knew ahead of the Sept. 11 terrorist attacks. He is now a contributor to Fox News.

Brought in as an executive vice president overseeing a new digital video enterprise now known as Hill.TV, Solomon continued to operate as a journalist, publishing news articles in the paper, while also playing a role on The Hill’s business side. That began to trouble colleagues within months of his hiring, according to internal memos and interviews with current and former staffers.

In late October 2017, The Hill published a story on the decisive role of Sen. Susan Collins, R-Maine, in the upcoming vote on the Trump administration’s tax bill. The article, authored by two journalists who reported to Solomon, included a quote from the executive director of Job Creators Network, a conservative group that claimed the bill would help small-business owners in Maine.

Soon after, Johanna Derlega, then The Hill’s publisher, wrote two memos to the company’s president, Richard Beckman, worrying that Solomon was tearing down the traditional wall separating the business side and the news coverage. She noted that Solomon had negotiated a nearly $160,000 advertising deal with Job Creators Network, targeting business owners in Maine. Solomon then had a quote from that group’s director inserted in the story.

Solomon “pops by the advertising bullpen almost daily to discuss big deals he’s about to close,” Derlega wrote, adding, “If a media reporter gets ahold of this story, it could destroy us.”

“While I highlight this one example, John has been given the freedom, and possibly financial upside, to work with advertisers while clearly sitting within editorial,” Derlega wrote.

Six months later, in April 2018, Derlega was forced out of The Hill. The Hill’s owner, president and top editors haven’t responded to detailed questions about Derlega’s memos and Solomon’s tenure at the paper. A spokesman for the advertiser, Job Creators Network, didn’t respond to an email seeking comment.

In interviews with ProPublica this week, Solomon repeatedly declined to discuss his activities on The Hill’s business side, saying, “I just simply can’t talk about anything business related with The Hill.”

A month later, the paper’s editor in chief, Bob Cusack, emailed staff that “effective immediately” Solomon would no longer publish stories under the banner of news but instead would be an “opinion contributor.”

From this new perch, Solomon broke in early spring what seemed to be an explosive piece of news: claims by Yuriy Lutsenko, then Ukraine’s top prosecutor, that a U.S. diplomat, serving under President Barack Obama, presented him a list of people and groups he could not prosecute. Additionally, Lutsenko said that he was reviving a probe into the Ukrainian natural gas company Burisma Holdings, seeking to determine whether Joe Biden, as vice president, interfered with the initial inquiry to protect his son Hunter, who sat on Burisma’s board.

Behind the scenes, Parnas had been central to connecting Solomon with Lutsenko. In a March 2019 email that included the businessman, the columnist wrote that he’d “just got word from Lev that the prosecutor general has agreed to do an interview tomorrow.”

Parnas watched Lutsenko’s interview live, inside the control room of The Hill’s TV studio. Solomon explained that he called in the businessman to act as a translator, but in the end his services were not needed.

Solomon recalls first encountering Parnas through Pete Sessions, the once-powerful Texas Republican member of Congress who is now in the middle of the Trump impeachment inquiry. Sessions accepted campaign donations from Parnas and Fruman, and had met with the two men as they sought to oust an American diplomat in Ukraine. Later, Sessions wrote a letter to Secretary of State Mike Pompeo, urging him to replace the envoy Marie Yovanovitch, who had been the subject of extensive criticism in the conservative media. She was later fired and is a key witness for House Democrats trying to impeach the president.

Sessions, who has denied knowledge of the campaign finance scheme laid out by prosecutors, told ProPublica that he has no connection to Solomon.

“I don’t know John,” he said.

Solomon says his personal attorneys, Joe diGenova and Victoria Toensing, a husband-and-wife legal team that regularly represents conservative luminaries, set up his first formal meeting with Parnas. He asserted that his editors “were aware” that he was seeking help from diGenova and Toensing on matters concerning Ukraine.

“I was doing that as an extra layer of protection,” Solomon said. “And so everything — everything — was above board. Everybody knew about it. I was just trying to be careful.” diGenova and Toensing did not respond to a request for comment.

As he compiled material for subsequent columns, Solomon and Parnas continued to work closely. In late March, less than a week after the first piece featuring Lutsenko appeared in The Hill, Solomon sent files via Dropbox to Parnas containing financial records purporting to be connected to Biden’s son. Around the same time, Solomon also sent Toensing and diGenova what appeared to be an advance copy of a Ukraine-related story. The Daily Beast reported that the email was included in a State Department Inspector General’s Office package of material turned over to lawmakers.

Solomon acknowledged that Parnas helped set up the Lutsenko interview, but he says he had originally requested it through official channels. Solomon maintains his relationship with the businessman was a typical one a reporter would have with a source. “Lev would call me,” he said, “and offer things he was hearing on the ground and I would look into some things.”

As Solomon’s relationship with Parnas developed, he learned over time that the businessman “was working for many people or several people in Ukraine,” including Giuliani and Solomon’s lawyers. Politico first reported Solomon’s lawyers also represented the Ukrainian oligarch. Giuliani hasn’t responded to messages seeking comment.

Solomon defended his work, including his reporting on the so-called do-not-prosecute list, which he said he went through “enormous efforts” to verify. “At the end of the day,” Solomon said. “it doesn’t matter what Lev Parnas did. It matters what I did.”

But a month after Lutsenko’s Hill TV appearance, the former Ukrainian prosecutor backed off of his allegations. He told a Ukrainian-language publication that he himself was the one who asked the U.S. ambassador for the list of supposedly untouchable figures. The State Department said there was never any list, calling it an “outright fabrication.” And Lutsenko told the Los Angeles Times last month that he saw no evidence of wrongdoing that would justify an investigation into Biden’s son’s business dealings in his country.