– The chairman of the House Oversight and Reform Committee revealed information Thursday that he said showed Ivanka Trump and Jared Kushner used private messaging services for official White House business in a way that may have violated federal records laws.

The chairman, Elijah Cummings, D-Md., said that a lawyer for Ivanka Trump, President Donald Trump’s daughter, and Kushner, the president’s son-in-law and senior adviser, told the committee late last year that in addition to a private e-mail account, Kushner uses an unofficial encrypted messaging service, WhatsApp, for official White House business, including with foreign contacts.

Cummings said the lawyer, Abbe Lowell, also told lawmakers that Ivanka Trump did not preserve some e-mails sent to her private account if she did not reply to them.

Democrats have barely been able to contain their frustration at what they see as a dark irony in the findings — and in earlier news reports about the couple’s use of private e-mail accounts. Donald Trump made Hillary Clinton’s use of a private e-mail server while she was secretary of state a central line of attack in his 2016 campaign for president. Even after the FBI declined to charge Clinton for her practices and handling of classified information, Republicans in Congress have continued to pick away at the case.

Lowell could not say if Kushner had communicated classified information on the messaging service, Whats­App. He asserted that because Kushner took screenshots of the communications and sent them to his official White House account or the National Security Council, his client was not in violation of federal records laws.

In a letter Thursday disclosing the new information, Cummings said the findings added urgency to his investigation of possible violations of the Presidential Records Act by members of the Trump administration, including Kushner and Ivanka Trump. He accused the White House of stonewalling his committee on information that it had requested months ago, when Republicans still controlled the House.

“The White House’s failure to provide documents and information is obstructing the committee’s investigation into allegations of violations of federal records laws by White House officials,” Cummings wrote. He said he would “be forced to consider alternative means to obtain compliance” if documents he requested about White House communications and record keeping were not shared with the committee, an indication he could subpoena them.

Steven Groves, a White House lawyer, said the White House would review Cummings’ letter and “provide a reasonable response in due course.”

Lowell accused Cummings of misrepresenting parts of what he told lawmakers last year and disputed suggestions that either of his clients had broken the law.

The oversight committee first began scrutinizing the use of private communications services at the White House in 2017 amid news reports that Kushner had used a private e-mail account for government business and then that Ivanka Trump had done the same.