The Hill also raised questions — which it says remain unanswered — about Solomon's relationships with President Donald Trump's personal lawyer Rudy Giuliani and his associate Lev Parnas, who were central figures driving the suggestion of wrongdoing by the Bidens in Ukraine. Though Solomon has claimed he relied on Parnas as a "facilitator" to connect him with sources in Ukraine, Hill staff said the communications uncovered in the House impeachment investigation pointed to deeper ties.

"The true nature and extent of Parnas's role in Solomon's work remain unclear but potentially troubling," they wrote. "While Solomon has insisted that Parnas was simply facilitating contacts or arranging interviews in his native Ukraine, the number of alleged contacts or apparent references to Solomon in emails, text messages and other materials released by Parnas to congressional investigators raises questions about his involvement."

The internal review by The Hill of Solomon's work answers few of the deeper questions about his role in the Ukraine saga. But it underscores the web of contacts that Trump relied on as his eyes and ears in Ukraine, bypassing official State Department channels in order to press the government there to investigate the Bidens, as well as other Democrats based on a debunked conspiracy theory that Ukraine — not Russia — hacked the Democratic Party in 2016.

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Solomon's columns were routinely amplified by Trump and featured on Fox News' prime-time opinion shows. They also formed a significant part of the rebuttal to the House's impeachment charges by Trump's allies in Congress and his legal team.

The network of Trump associates entangled in the Ukraine scandal also includes Joseph DiGenova and Victoria Toensing, husband and wife attorneys and allies of Trump whom Solomon quoted sporadically over the years on matters related to Ukraine. DiGenova and Toensing also represent Dmitry Firtash, a Ukrainian oligarch with Russian ties who is fighting extradition to the United States on conspiracy and bribery charges. The Hill indicated that Solomon, in his columns quoting Toensing, failed to disclose that the pair also represented him.

"As part of this review, The Hill is adding disclosures — to Solomon’s news stories, opinion columns, and relevant Hill.TV appearances — that should have been made at the time of publication," the publication wrote.

The Hill found that it failed in part by permitting Solomon to engage in work that had the appearance of investigative journalism despite being labeled as "opinion," a distinction that readers may have found confusing and that Solomon's boosters routinely blurred or ignored. The publication also notes that Solomon, who left the publication to start a media company, continues to stand by his work.

"When appearing on television to discuss his Ukraine columns, Solomon was not typically labeled an opinion writer by the broadcast programs. The Hill did not contact television producers to label Solomon as an opinion columnist. It should have," the review concluded. "Solomon’s subsequent appearances on Fox News where he was often identified as an investigative journalist further potentially blurred the distinction between news and opinion in the minds of some readers."

