Federal prosecutors are taking an interest in an episode where Rudy Giuliani associates Lev Parnas and Igor Fruman tried to recruit top Ukraine energy official Andrew Favorov in a takeover of the state oil and gas company, Naftogaz, according to the Wall Street Journal.

The episode happened last March at a conference in Texas, as first reported by the Associated Press.

Parnas and Fruman, along with oil magnate Harry Sargeant III, approached Favorov with a plan to oust Naftogaz CEO Andriy Kobolyev, an anti-corruption crusader within the company, to elevate Favorov to the top spot. In exchange, Favorov would annually accept 100 shipments of American natural gas in Ukraine.

The men told him that the plan had the President Donald Trump stamp of approval, and that the President was planning to oust former Ambassador Marie Yovanovitch. That revelation came nearly three months before she was ultimately booted.

Per the Wall Street Journal, Parnas and Fruman asked Favorov if he was a Republican before telling him that they wanted him to be “their guy.”

Favorov immediately reported the exchange to his former business partner, who told an official at the U.S. embassy in Ukraine, who told the press. Two weeks after the meeting with Favorov, Parnas and Giuliani debriefed former Trump campaign adviser Healy Baumgardner, according to the AP report. Giuiani denied the reporting, claiming that their meeting was about business interests in Uzbekistan.

Prosecutors are investigating Giuliani’s role in these attempts to mold a more hospitable atmosphere for Parnas and Fruman’s business interests, namely their purported natural-gas company, Global Energy Producers, and what was financially or politically in it for him.

The story of the Ukraine backchannel-Naftogaz connection has long been a planet orbiting the President’s the pressure campaign, and involves another major player.

Energy Secretary Rick Perry initially expressed his interest in expanding Naftogaz’s supervisory board to include two Texans, one of whom contributed to Perry’s campaign. He gradually made clear that the Trump administration wanted the whole board replaced — including a former Obama administration official — with people “reputable in Republican circles,” per AP.

John Dowd, a former Trump attorney who initially represented Parnas and Fruman, implicated Perry in the Favorov meeting as well, which he claims came about when his clients were approached by Naftogaz officials.

The plan “was presented to Secretary Perry to see if they could get it together,” he said.