Senate Minority Leader Charles E. Schumer on Thursday called for an investigation into the trading of medical industry stocks by President-elect Donald Trump’s nominee to lead the Department of Health and Human Services. The Trump transition team responded by highlighting recent trading in pharmaceutical stocks by three Democratic senators.

Schumer, a New York Democrat, asked that the House Office of Congressional Ethics look into Price’s trading in health care stocks, an issue that Roll Call investigated in a story last month. Price last year traded shares of firms such as Gilead Sciences, Aetna and CVS Health Corp, while serving on the Ways and Means Health Subcommittee.

“We don’t know if he broke the law,” Schumer said at a press conference, adding that there were “enough serious questions to warrant a serious investigation before any hearing is held on Congressman Price to become secretary of HHS.”

Schumer said Price should have to address questions about his trading in a public forum as well as face an investigation into whether his position in the House aided him in his trades.

Joining Schumer in his demands for an investigation were Sen. Ron Wyden of Oregon, the ranking Democrat on the Senate Finance Committee, and Sen. Patty Murray of Washington, the ranking Democrat on the Health, Education, Labor and Pensions panel.

Finance has the responsibility for handling HHS secretary nominations. It’s been notably tardy in announcing a hearing date on Price’s nomination, although both President-elect Donald Trump and the Republican-led Congress put health policy at the top of their agenda for this year. Other Senate committees have already slated hearings for the nominees to lead the State, Justice, Labor, Transportation, Education and Homeland Security departments. The HELP Committee, which plays an advisory role on the HHS nomination, is tentatively planning a Jan. 18 hearing on Price.

[Drug Stock Trades of Trump Health Secretary Pick Draw Criticism]

Waiting for the result of an Office of Congressional Ethics investigation into Price’s trades could delay the potential confirmation process for some time. The office declined to comment on Thursday. Information posted on the OCE website suggests that it could take several months to produce information on Price’s trading if the office decides to move forward with an investigation and refer the matter to the Ethics Committee for review.

The liberal watchdog group Public Citizen on Thursday asked for both the OCE and the Securities and Exchange Commission to look into Price’s trading. The group said congressional financial disclosure reports show that Price conducted more than 630 trades on the stock market, many of which involve the pharmaceutical and health care sectors. The group also asked for an inquiry into the trades of Rep. Chris Collins. The New York Republican and Price both have stakes in the Australian biotech Innate Immunotherapeutics, according to Public Citizen. Collins serves on the board of directors for the firm, according to its website.

In response to the Democratic criticism of Price, Phillip Blando, a spokesman for the Trump transition team, raised questions about stock trades made by Democratic senators. Sen. Sheldon Whitehouse of Rhode Island, for example, also traded last year in pharmaceutical stocks, according to Senate financial disclosure forms. Like Price, Whitehouse traded in shares of the biotech firm Gilead Sciences, a maker of hepatitis treatments that’s been a target of robust criticism by Wyden and Iowa GOP Sen. Charles E. Grassley. Gilead’s breakthrough hepatitis drug, Sovaldi, initially reached the domestic market with a price of $1,000 a pill. The costly medicine took a notable fiscal toll on Medicare and Medicaid as well as the Bureau of Prisons.

“Hypocrisy is apparently alive and well this morning in Washington,” Blando said in a statement. “The reality is that Dr. Price’s 20-year career as an orthopedic surgeon and a fiscal conservative make him uniquely qualified to lead HHS.”

Blando also mentioned trades made by Democratic Sens. Mark Warner of Virginia and Thomas R. Carper of Delaware. A spokeswoman for Warner said that his investments are managed by an independent trustee and have been since he became governor of Virginia in 2002.

Bridget Bowman contributed to this report.