WASHINGTON (AP) — James Biden arrived for a private interview Wednesday on Capitol Hill as part of House Republicans’ impeachment inquiry into his brother, President Joe Biden.

The interview with the younger Biden is the latest in a series that GOP lawmakers have conducted recently as they seek to rebuild momentum for an impeachment process that has stalled in recent months.

Criticism over the lack of evidence directly related to the president has grown even among those in the Republican Party who have thrown cold water on allegations that Biden and his family used his office to advance their financial affairs. The investigation was undercut again last week when an FBI informant who claimed there was a multimillion-dollar bribery scheme involving the president, his son Hunter, and a Ukrainian energy company was charged with fabricating the story.

The informant’s claims had been central to the Republican effort in Congress to investigate the president and his family. An attorney for Hunter Biden, who is expected to give a deposition next week, said the charges show the probe is “based on dishonest, uncredible allegations and witnesses.”

Both James and Hunter were subpoenaed by the committee in November. A lawyer for James Biden said at the time that there was no justification for the subpoena because the committee had already reviewed private bank records and transactions between the two brothers. The committee found records of two loans that were made when Joe Biden was not in office or a candidate for president.

“There is nothing more to those transactions, and there is nothing wrong with them,” lawyer Paul Fishman said in a statement in November. “And Jim Biden has never involved his brother in his business dealings.”

Republicans have pushed back, saying the evidence they have gathered since early last year paints a troubling picture of “influence peddling” by Biden’s family in their business dealings, particularly with international clients. But thus far, nearly every interview they have conducted has failed to support their widespread allegations.