Jared Kushner. Drew Angerer/Getty Images A top Democrat launched an investigation Monday into White House senior adviser Jared Kushner's use of private email while serving in the Trump administration.

Rep. Elijah Cummings of Maryland, the ranking member of the House Committee on Oversight and Government Reform, sent a letter to Kushner following Politico's report on Sunday detailing the adviser's use of private email while serving in the White House.

"Before requesting copies or calling for the public release of all official emails you sent or received on your personal email account, I first request that you preserve all official records and copies of records in your custody or control and that you provide the information requested below," Cummings wrote. "Your actions in response to the preservation request and the information you provide in response to this letter will help determine the next steps in this investigation."

Kushner, President Donald Trump's son-in-law, set up a private email account in December and has used it since to discuss official government business with fellow administration officials, Politico reported.

Some of those officials included former White House chief of staff Reince Priebus, former White House chief strategist Steve Bannon, and National Economic Council chairman Gary Cohn.

Though Kushner's lawyer said the adviser "uses his White House email address to conduct White House business," he admitted that Kushner had utilized a personal email account to discuss government business.

"Fewer than 100 emails from January through August were either sent to or returned by Mr. Kushner to colleagues in the White House from his personal email account," the lawyer said. "These usually forwarded news articles or political commentary and most often occurred when someone initiated the exchange by sending an email to his personal rather than his White House address."

"Kushner has adhered to government record-keeping requirements by forwarding all the emails to his account," the lawyer added.

Cummings highlighted a March 8 request that he and former Oversight Committee chairman Jason Chaffetz sent to White House Counsel Donald McGahn asking whether any senior-level administration officials used private email accounts to conduct official government business. Cummings' release pointed to an April 11 response from White House Director of Legislative Affairs Marc Short, who said, "There are no senior officials covered by the PRA [Presidential Records Act] with multiple accounts."

"This statement appears to be inaccurate," Cummings wrote. "Although it is possible that Mr. Short was referring to senior officials with multiple official governmental email accounts and that he did not know about your personal email account at the time he wrote this letter to the committee."

Cummings additionally asked Kushner to provide the addresses for all private email accounts he used to conduct any government business, a list of all the emails he either sent or received at those addresses that involved official government business, and information about the security of the domain he used.