US Republican Representative Jim Jordan, a close confidante of former President Donald Trump, announced on Sunday he would not cooperate with a US House committee investigating last year's attack on the Capitol, Reuters reported.
The panel had asked Jordan to disclose conversations he had with Trump on January 6, 2021, the day of the Capitol riots.
"This request is far outside the bounds of any legitimate inquiry, violates core constitutional principles and would serve to further erode legislative norms," Jordan said in a letter to committee chairman, Democrat Bennie Thompson.
His rejoinder came after the panel requested an interview with Jordan last month.
In May, the US House of Representatives passed a bill to form a commission to probe the January 6 attack on the Capitol. The bill was approved in a 252-175 vote, with 35 Republicans joining all Democrats in support.
Two days later, however, Senate Republicans blocked the legislation. Senators voted 54-35 on the House-passed bill, falling short of the 10 GOP votes needed to get it over an initial hurdle.
Without any pathway forward in the Senate, House Speaker Nancy Pelosi announced she would use her power to pursue a select committee in the House that will be controlled by Democrats.
The House committee has subpoenaed a slew of close associates of Trump. The House has already voted to hold two of them - former White House senior advisor Steve Bannon and former White House chief of staff Mark Meadows - in contempt of Congress for noncompliance with the subpoena.
House Republicans nominated Jordan to the committee investigating the riot, but Pelosi rejected the choice, citing his support of Trump's false claims of election fraud.
Two Republicans, Representatives Liz Cheney and Adam Kinzinger, are members of the committee.