WASHINGTON — A deeply divided House committee debated Tuesday whether to pass a high-profile bill that would prohibit members of Congress from buying and selling stocks based on non-public information they learn about through their work on Capitol Hill.

Several panel members, backed in part by the testimony of a Securities and Exchange Commission official, said the measure is not needed because existing laws and congressional ethics rules ban such action. They also said they worry that the bill, known as the Stop Trading on Congressional Knowledge Act, could be used to unfairly tarnish members.

“I’m concerned that this could become a witch hunt,” Rep. Carolyn McCarthy, D-N.Y., said during the two-hour Financial Services Committee hearing. “Members are not out to make a quick buck.”

The hearing struck a very different tone from one held last week on two similar bills before a Senate committee, where members said the bills should be retooled and quickly passed to restore the public’s confidence in Congress.

The Senate and House measures would ban members and their staffs from trading on information they learn about as they craft legislation. They also would require that stock trades be reported within 90 days.

Robert Khuzami, head of the SEC’s division of enforcement, said current laws could be used to go after a lawmaker, but successful prosecution could be difficult. He recommended passage of a fairly simple bill stating that members have a “duty of trust and confidence” not to use non-public information for “private gain.”