House Republicans said Wednesday they're investigating whether President Biden sought to "obstruct" Hunter Biden's cooperation with their committees' impeachment inquiry.

Driving the news: Hunter Biden said earlier this month he would defy a subpoena and not sit for a closed-door deposition, prompting House Judiciary Committee Chair Rep. Jim Jordan (R-Ohio) and Oversight Committee Chair James Comer (R-Ky.) to announce they would begin contempt of Congress proceedings against the president's son.

• Jordan and Comer announced Wednesday they had sent a letter to White House Counsel Edward Siskel, calling for "all documents and communications sent or received by employees of the Executive Office of the President regarding Hunter Biden's deposition."

Details: "In light of an official statement from the White House that President Biden was aware in advance that his son, Hunter Biden, would knowingly defy two congressional subpoenas, we are compelled to examine as part of our impeachment inquiry whether the President engaged in a conspiracy to obstruct a proceeding of Congress," Comer and Jordan wrote in a letter to Siskel.

• The letter points to comments by White House Press Secretary Karine Jean-Pierre earlier this month that "the president was certainly familiar with what his son was going to say" when Hunter Biden made a rare public statement that criticized Republicans for their investigation.
• "Ms. Jean-Pierre's statement suggests that the President had some amount of advanced knowledge that Mr. Biden would choose to defy two congressional subpoenas," Comer and Jordan wrote.
• "In light of Ms. Jean-Pierre's statement, we are compelled to examine the involvement of the President in his son's scheme to defy the Committees' subpoenas."

Context: Hunter Biden said last month that he would be willing to testify before the House Oversight Committee, but only in public. However, Comer said that this amounted to "a demand that he receive special treatment."

Of note: Comer previously said that House Republicans "have so many documents" in the investigation that they "can bring these people in for depositions or committee hearings, whichever they choose, and we can ask these questions with evidence."

What we're watching: The impeachment inquiry has yet to find direct evidence of any wrongdoing by the president, leading to skepticism among some Senate Republicans who would be the jurors if there were a Senate trial.

• Representatives for the White House did not immediately respond to Axios' request for comment.

Go deeper: Hunter Biden goes on attack against GOP, believing it helps dad

Editor's note: This article has been updated with further context.