Treasury Department lawyers consulted with the White House general counsel’s office about the potential release of President Trump’s tax returns before House Democrats formally requested the records, Treasury Secretary Steven Mnuchin said Tuesday.

Mnuchin had not previously revealed that the White House was playing any official role in the Treasury Department’s decision on releasing Trump’s tax returns.

Democrats are asking for six years of Trump’s returns, using a federal law that says the treasury secretary “shall furnish” the records upon the request of House or Senate chairmen. The process is designed to be walled off from White House interference, in part because of corruption that took place during the Teapot Dome scandal in the 1920s.

Mnuchin revealed the discussions during a congressional hearing. He said he had not personally spoken with anyone from the White House about the tax returns, but he said that members of his team had done so.

“I believe that the communication between our legal department and the White House general counsel was informational,” Mnuchin told a House Appropriations subcommittee. “We had obviously read in the press that we were expecting this. I personally wasn’t involved in those conversations.”

Mnuchin added that he was never briefed on the content of the discussions.

At a separate congressional hearing in the afternoon, Mnuchin said Treasury officials did not seek the White House’s “permission” as to whether to release the tax returns, and he also said he did not view the meeting as “interference.”

But congressional Democrats signaled concern with any White House involvement in the process, with Rep. Carolyn B. Maloney (D-N.Y.) saying the White House should be not be playing a role in the release of the tax records.

“I think the fact that there was any communication with the White House about this is deeply troubling and certainly violates the spirit of the law, if not the letter of the law, and I think we need to get to the bottom of this,” she told Mnuchin at the hearing.

On April 3, House Ways and Means Committee Chairman Richard E. Neal (D-Mass.) requested the returns, both for Trump’s personal income and a range of his businesses. The request was sent to Internal Revenue Service Commissioner Charles Rettig. Neal said he wanted the records to be released by April 10, citing federal law that directs the information be disclosed upon request.

“Congress, as a coequal branch of government, has a duty to conduct oversight of departments and officials,” Neal said when he requested the tax returns. “The Ways and Means Committee in particular has a responsibility to conduct oversight of our voluntary federal tax system and determine how Americans — including those elected to our highest office — are complying with those laws.”

On April 5, lawyers for Trump sent the Treasury Department general counsel a letter telling him not to release the records until the Justice Department has issued a new legal opinion. Over the weekend, White House acting chief of staff Mick Mulvaney said Democrats would never obtain the tax returns, though he did not say how he was sure this would be the case.

“Keep in mind that that’s an issue that was already litigated during the election,” Mulvaney said on Fox News on Sunday. “Voters knew the president could have given his tax returns, they knew that he didn’t, and they elected him anyway, which is, of course, what drives the Democrats crazy.”

Mnuchin, at the hearing Tuesday, would not say how he planned to proceed.

“It is being reviewed by the legal departments, and we look forward to responding to the letter,” Mnuchin said.

Later in the hearing, Mnuchin criticized Democrats for requesting the tax returns, saying they should be glad Republicans did not seek the tax returns of Democrats when the GOP controlled the House of Representatives before the 2018 midterm elections.

“I am sure there are many prominent Democrats who are relieved that when Kevin Brady [of Texas] was chairman of the committee, he didn’t request specific returns,” Mnuchin said.

He did not explain who he was referring to, but he said this list could include Democrats in Congress and their financial supporters outside Washington.

Rettig, of the IRS, also weighed in on the matter Tuesday and suggested that he would play the principal role in deciding whether to release the returns.

He told lawmakers Tuesday that the decision over whether to release Trump’s tax returns was his, but also that it was one to make “with the supervision of Treasury,” noting that the IRS is a part of the Treasury Department. Rettig said he has discussed Neal’s request with Mnuchin, but he added that Mnuchin did not order him to reject the request or tell him how to handle the returns.

The request gives Rettig until Wednesday to respond to his request. But despite questions from House Democrats on a financial services committee, Rettig would not say whether he had asked IRS counsel if the decision is his to make.

Asked whether there was communication between the IRS and White House over Trump’s tax returns, Rettig said, “To my knowledge, absolutely not.”

Trump has given a range of explanations for why he has not released his tax returns. He has frequently promised to release his returns once an audit of these returns is completed by the IRS. But he has not provided information to substantiate that there is, in fact, an audit underway.

Other presidential candidates, dating back to the Nixon administration, have released their tax returns.

Congress updated the tax code in 1924 to give the chairmen of the House and Senate tax-writing committees the ability to obtain anyone’s tax returns even if the request was opposed by the White House.

That is because of the Teapot Dome scandal in the early 1920s. In the Warren Harding administration, Interior Secretary Albert Fall had improperly leased Navy petroleum reserves to private companies without allowing competitive bids. He would eventually go to jail for accepting bribes as part of the scheme, and lawmakers decided after the scandal that they needed access to more information about the economic interests of top White House officials.

Jeff Stein contributed to this report.