WASHINGTON – Former national security adviser John Bolton wanted no part of what he derided as the White House's "drug deal" to pressure Ukraine into investigating Democratic presidential candidate Joe Biden, a former White House official told congressional investigators on Monday, according to reports of her testimony from The New York Times and NBC News.

Fiona Hill, who served as the National Security Council's senior director for Europe and Russia, spent more than 10 hours fielding questions from three House panels behind closed doors.

Her testimony was part of an impeachment inquiry into allegations President Donald Trump used military aid as leverage to get the Ukrainians to dig into an energy company that included the former vice president's son Hunter on its board. Ukrainian officials have said they uncovered no evidence of wrongdoing on the part of the Bidens.

Hill testified that Bolton told her to inform National Security Council lawyer John Eisenberg of the push for a fresh investigation by acting White House chief of staff Mick Mulvaney, Trump's personal attorney Rudy Giuliani and Gordon Sondland, the U.S. ambassador to the European Union, the reports said.

Mulvaney, Giuliani and Sondland also wanted Ukrainian officials to explore the possibility of a Ukrainian role in 2016 election interference.

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Hill said Bolton advised her to contact Eisenberg after a July 10 meeting with senior Ukrainian officials in which Sondland brought up the issue of investigations, The Wall Street Journal reported.

Bolton told her he wasn't part of "whatever drug deal Sondland and Mulvaney are cooking up," unnamed sources who witnessed Hill's testimony told the Times. He also reportedly referred to Giuliani as "a hand grenade who’s going to blow everybody up."

"I always liked and respected John," Giuliani said of Bolton in response to Hill's testimony, according to NBC News. "I’m very disappointed that his bitterness drives him to attack a friend falsely and in a very personal way. It’s really ironic that John Bolton is calling anyone else a hand grenade. When John is described by many as an atomic bomb."

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Hill told lawmakers that Giuliani's role circumvented the normal national security processes and procedures for forming foreign policy.

The Times reported that she confronted Sondland about what she considered the rogue foreign policy he was instituting in Ukraine, which is not part of the EU and therefore not normally under the ambassador to the EU's purview.

Sondland told her that he was in charge of Ukraine. When she asked who had given him that authority, he replied that the president had, according to the Times.

Sondland is expected to testify Thursday.

Contributing: Christal Hayes and Bart Jansen

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