WASHINGTON The White House on Friday challenged the validity of an impeachment inquiry run by Republicans in the U.S. House of Representatives into President Joe Biden's son's business dealings.

A letter from White House legal counsel Dick Sauber sent to House Republicans leading the inquiry said the probe was not valid since the House did not vote to authorize it. A copy of the letter was seen by Reuters.

"You appear so determined to impeach the president that you have misrepresented the facts, ignored the overwhelming evidence disproving your claims, and repeatedly shifted the rationale for your 'inquiry,'" Sauber wrote to House Oversight Chairman James Comer and House Judiciary Chairman Jim Jordan.

House Committee on Oversight and Accountability Chairman James Comer, a Republican from Kentucky, said, "If President Biden has nothing to hide, then he should make his current and former staff available to testify before Congress about his mishandling of classified documents."

Republicans have accused Biden of profiting from the business dealings of his son, Hunter, while serving as vice president between 2009 and 2017.

They have not found any evidence of misconduct by Biden himself. The White House says Biden has done nothing wrong and Republicans have no basis for an impeachment inquiry.

Sauber said recent subpoenas and demands for congressional testimony from various White House officials and Biden family members were irresponsible.

"These requests appear to be motivated by a desire to boost your subpoena numbers, as Chairman Jordan tweeted just this week, rather than any legitimate investigative interest," Sauber said.

(Reporting by Steve Holland and Makini Brice; Editing by Richard Chang)