NEW YORK (Reuters) – A U.S. House of Representatives panel said on Friday it should not have to comply with a federal regulator’s demand for documents sought for an insider-trading probe involving the staff director of a subcommittee and a lobbyist.

The House Ways and Means Committee argued in a court filing that U.S. District Judge Paul Gardephe in New York should deny the Securities and Exchange Commission’s attempt to subpoena documents from the committee and its healthcare subcommittee staff director Brian Sutter.

ADVERTISEMENT

The SEC went to court June 20 to enforce subpoenas it issued as it sought information related to a probe into whether Sutter leaked material nonpublic information about Medicare reimbursement rates to Mark Hayes, a lobbyist at Greenberg Traurig LLP.

The committee’s filing called the SEC subpoena “a remarkable fishing expedition for congressional records.” It said the U.S. Constitution shields the panel and Sutter from being compelled to testify or produce documents.

A request for comment from the SEC was not immediately returned.

The dispute between the House committee and the regulator could test the boundary of the SEC’s powers to compel the legislative branch of government to cooperate with its enforcement of the federal securities laws.

In previous court filings, the SEC said Hayes spoke with Sutter the same day that the Centers for Medicare and Medicaid Services announced reimbursement rates for the Medicare Advantage program.

ADVERTISEMENT

The regulator said Hayes then emailed the brokerage firm Height Securities, which shortly afterward sent its clients a “flash alert” suggesting the deal could help insurance companies such as Humana Inc and Health Net Inc .

Share prices of both companies jumped after the report was issued.

The SEC will have until July 11 to respond to the committee’s opposing arguments.

ADVERTISEMENT

The case is SEC v. Committee on Ways and Means of the U.S. House of Representatives et al, U.S. District Court, Southern District of New York, No. 14-mc-00193.

(Reporting by Luciana Lopez in New York and Nate Raymond and Sarah Lynch in Washington; Editing by David Gregorio)