(CNN) Conservative lawyer John Eastman is suing Verizon and the House select committee investigating the January 6 attack on the US Capitol over a subpoena issued by the panel for his phone records, according to court documents.
Eastman argues that the committee's subpoena is "invalid" for several reasons, and notably he attempts to differentiate between the rallies held on January 6 and the riot at the Capitol that day.
"Without prior notice to Dr. Eastman, the J6 Committee issued a subpoena to Verizon requesting records for Dr. Eastman's personal cell phone. The subpoena seeks nine categories of information on Dr. Eastman's personal cell phone use over a three-month period. The subpoena does not contain any provision for protection of attorney client privilege," the court documents say.
"The J6 Committee's subpoena to Verizon is invalid for several reasons. First, public statements by J6 Committee members make clear that the Committee is attempting to exercise a law enforcement function, rather than genuine legislative activity. The United States Congress has no power to issue subpoenas for law enforcement purposes," the documents add.
Eastman goes on to argue that the subpoena is invalid because it "was issued in violation of House Rules and the J6 Committee's own authorizing resolution" and violates his Fourth Amendment right to privacy.
CNN has reached out to Verizon for comment.
CNN previously reported that the committee has issued subpoenas seeking call record data from more than 100 individuals as part of the probe, including former White House chief of staff Mark Meadows, who has also sued the panel.
The records sought by the committee do not include the content of calls but rather details about who called or texted whom, when and for how long, enabling the panel to draw a web of communications before, during and after the January 6 attack.
This story has been updated with additional context.