Treasury Secretary Steven Mnuchin testifies before the House Financial Services Committee hearing on "The Annual Testimony of the Secretary of the Treasury on the State of the International Financial System" in Washington, U.S., May 22, 2019. REUTERS/Mary F. Calvert

WASHINGTON (Reuters) - U.S. Treasury Secretary Steven Mnuchin on Wednesday said he had not discussed releasing President Donald Trump’s tax returns with the White House, and disagreed with an IRS memo that reportedly concluded he should release them to Congress.

Mnuchin told U.S. lawmakers he did not know who in the Internal Revenue Service had written the draft memo, which concluded that tax returns must be given to lawmakers unless the president takes the rare step of asserting executive privilege.

He said he had seen a copy of the memo, first reported by the Washington Post, only on Wednesday and had not reviewed it. But he said he did not believe it contradicted his reasoning for denying a request from the House of Representatives Ways and Means Committee for six years of Trump’s tax returns.

Mnuchin last week rejected a demand for the tax records, saying the panel lacks “a legitimate legislative purpose” for obtaining the documents that Democrats view as critical to their efforts to investigate Trump and his presidency.

The newly disclosed draft memo was looking at a different issue, Mnuchin told a hearing of the House Financial Services Committee. “That memo, as I understand, is addressing a different issue and is not addressing the issue that we and the Department of Justice looked at,” he said.

Mnuchin said he had been advised it would be unlawful to release the returns, and underscored that the memo that reportedly contradicted that advice had only been in draft form.

“We’re trying to find out who wrote the memo, where it came from, when it was and why it wasn’t distributed,” he said. “We confirmed that I and the (IRS) commissioner were not aware of that letter and had not seen it.”

The Treasury secretary also insisted he had not discussed the issue of releasing the tax returns with Trump or anyone else at the White House.

“I have had no conversations ever with the president or with anyone in the White House about delivering the president’s tax returns to Congress,” he said.