WASHINGTON – Senior White House aide Jared Kushner uses the encrypted messaging service WhatsApp to conduct business and talk with foreign leaders, according to statements from his attorney released by Democrats on Thursday.

Back in December, Kushner's attorney, Abbe Lowell, told Rep. Elijah Cummings and then-House Oversight Committee Chairman Trey Gowdy that Kushner uses the app to communicate with foreign leaders in his official capacity as a senior adviser to President Donald Trump, according to a letter released by Cummings, D-Md., that was sent to White House Counsel Pat Cipollone. It was the first time the revelations, and meeting, were made public.

After the release of the letter, which also accused Kushner's wife, Ivanka Trump, and several high-profile members of the Trump administration of using private emails for business, Lowell responded by saying aspects of what Cummings said was "not completely accurate" and seemed to push back on allegations that Kushner used encrypted messaging to talk with foreign leaders, according to a letter Lowell sent to Cummings that was obtained by Politico.

"I said he has used those communications with 'some people' and I did not specify who they were," Lowell wrote. He added that Kushner, the president's son-in-law, has "numerous friends and contacts abroad."

Cummings, who chairs the Oversight Committee, accused the White House of obstructing the Oversight Committee's investigation by dragging its feet in turning over documents requested as part of a bipartisan investigation into the use of personal email accounts and other messaging software by White House staff. His letter also included a request for documents relating to the query by April 4 where he threatened to "consider alternative means" if the information was withheld.

Cummings laid out the progress made since the investigation was started in 2017, when Republicans led the House, and the information the committee has learned since that time. He included aspects of Lowell's December interview regarding Kushner's use of encrypted messaging and Ivanka Trump's personal email account.

"Specifically, when asked whether Mr. Kushner had ever used WhatsApp for official business, Mr. Lowell confirmed that Mr. Kushner has used—and continues to use—WhatsApp as part of his official duties in the White House," Cummings' letter states.

It continues, saying that when Lowell was asked whether Kushner had ever used the app to "communicate with foreign leaders, Mr. Lowell continued that Mr. Kushner "had communications with people outside the United States." The letter does not include a transcript or the exact words Lowell used in the interview, which was after multiple news outlets reported that Kushner had used WhatsApp to talk with Saudi Crown Prince Mohammed bin Salman. The reports surfaced as Saudi Arabia, specifically the crown prince, was under intense scrutiny for his role in the killing of Washington Post columnist Jamal Khashoggi.

Lowell, according to Cummings, did not say whether Kushner had talked about any classified material over the app, instead remarking "that's above my pay grade."

More:Trump administration pushed for sale of nuclear plants to Saudi Arabia, Democrats say in report

More:Jared Kushner's private emails: Here's what you need to know

More:Ivanka Trump sent hundreds of messages from personal email account, according to report

Lowell was also asked about Ivanka Trump's use of a personal email account to conduct business, something she was criticized for after news reports surfaced alleging that she had used a personal account to send hundreds of messages. The reports seemed to echo concerns made about Hillary Clinton's use of a private email during the 2016 election — something her father, President Donald Trump, focused on during his campaign.

Cummings wrote in his letter that Lowell said: "she continues to receive emails relating to official business on her personal email account and that she does not forward emails received through her personal account unless she responds to the email."

In the letter, Cummings also said the committee has obtained documents showing that former White House strategist Steve Bannon and former deputy national security adviser K.T. McFarland used personal email accounts to discuss a plan relating to the sale of nuclear plants to Saudi Arabia.

"These communications raise questions about whether these officials complied with the Presidential Records Act," Cummings wrote.