(CNN) Former acting Attorney General Matt Whitaker privately acknowledged Wednesday that he had raised concerns with his staff at the Justice Department about the scope of the Southern District of New York's case against former Trump attorney Michael Cohen, according to House Judiciary Chairman Jerry Nadler and Republican aides.

Whitaker thought some of the campaign finance charges against Cohen were "specious," pointing to the failed effort to prosecute former Sen. John Edwards on similar charges, according to GOP aides who were in the room during Whitaker's closed-door interview with Judiciary Committee leaders on Wednesday. But the Republican aides said he did not speak to the US Attorney's Office for the Southern District of New York about the case, instead saying he had internal discussions with Justice Department staff about his concerns.

Whitaker also did not deny talking with President Donald Trump about Cohen's case , in which the President was implicated in two federal crimes involving hush-money payments to silence his alleged affairs, Nadler told reporters Wednesday. The GOP aides said Whitaker did not remember having any conversations with Trump about the Cohen probe, and he said he would have remembered any contentious exchanges with the President about the case.

"Unlike in the hearing room, Mr. Whitaker did not deny that the President called him to discuss the Michael Cohen case and personnel decisions of the Southern District," Nadler said, referring to last month's daylong public hearing with Whitaker.

One Justice Department official in the room for the interview adamantly disagreed with Nadler's characterization of the conversation.

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