Rep. Elijah Cummings, chairman of the Committee on Oversight and Reform, penned a letter to White House counsel Pat Cipollone Thursday, alleging that Trump administration officials violated federal law.

The Maryland Democrat said in his letter that the committee’s investigation has found new information that “raises additional security and federal records concerns about the use of private email and messaging applications,” by President Donald Trump’s daughter, Ivanka, son-in-law Jared Kushner and several other administration officials.

Cummings’ letter demanded the counsel provide, by April 4, documents his committee previously requested but didn’t receive. It also asked for new documents relating to information the committee recently discovered about Ivanka Trump, Kushner and others including Trump’s former chief strategist Steve Bannon.

If the White House does not comply, the committee will “be forced to consider alternative means to obtain compliance,” the letter said.

[White House hasn’t provided ‘a single piece of paper’ to Oversight, despite 12 requests]

Cummings alleged in the letter that Ivanka Trump, violated The Presidential Records Act by receiving emails related to official business on her personal email account. 

The President’s daughter reportedly failed to forward emails she received on her personal account to an official White House email account.

The law requires emails related to official White House business received on personal mailing accounts, be forwarded to an official account of either the president or vice president within 20 days of receipt, the letter said.

Cummings raised concerns over Kushner’s use of messaging program WhatsApp “as part of his official duties in the White House.” 

Cummings’ letter said Abbe Lowell — Kushner and wife Ivanka Trump’s personal lawyer — met with him and then-committee chairman South Carolina Republican Rep. Trey Gowdy in December of 2018.

Lowell confirmed Kushner “had communications with people outside the United States” over the app before preserving the communications by taking screenshots and forwarding them to his official White House email account, the letter said. 

“When asked whether Mr. Kushner has ever used WhatsApp to discuss classified information, Mr. Lowell replied, ‘That’s above my pay grade,’” the letter said.

Lowell sent a letter to Cummings on Thursday, disputing some of the letter’s characterizations of their conversation regarding Kushner’s WhatsApp use, according to the Associated Press. 

Cummings revealed that the oversight committee obtained a document “that appears to show” K.T. McFarland, a former deputy national security advisor, conducted official business on her personal AOL account. 

“The document related to efforts by Ms. McFarland and other White House officials to transfer sensitive U.S. nuclear technology to Saudi Arabia in coordination with Tom Barrack, a personal friend of President Trump and the Chairman of President Trump’s inaugural committee,” the letter said.

The committee also acquired documents indicating former strategist Steve Bannon, while he still worked in the White House, pitched the plan of sharing delicate information with Saudi Arabia to Barrack.

Cummings said in the letter that he is concerned if the White House identified the use of personal emails, and whether it took steps to address the issue.

The Old Line State representative authored an op-ed in the Washington Post Wednesday, maintaining that the White House has repeatedly failed to produce any documents or witnesses related to the committee’s investigation.

Watch: What you missed from Michael Cohen’s congressional testimony

Correction: March 22, 2019, 5:53 p.m.| An earlier version of this story incorrectly described Tom Barrack’s role in an alleged transfer of sensitive U.S. nuclear technology to Saudi Arabia.