REUTERS/Pool

The House Oversight and Reform Committee is reviewing why Ivanka Trump, Jared Kushner, and other White House aides used personal email accounts to conduct official business, the panel's chair, Rep. Elijah Cummings (D-Md.), said Monday.

Lawmakers began looking at the use of personal accounts for work matters in 2017, and in a letter sent Monday, Cummings notified White House Counsel Pat Cipollone of the probe's expansion, sharing that the "purpose of this investigation is to determine why White House officials used non-official email accounts, texting services, and encrypted applications for official business." He also requested all pertinent communications sent by senior officials.

Last fall, The Washington Post reported that Trump sent almost 100 emails regarding government policies and White House business from her personal account, and Kushner's lawyer said his client used WhatsApp to discuss official duties.

Under the law, anything sent or received by a non-official email account must be forwarded to an official account within 20 days. The committee will investigate why this didn't happen, and whether White House officials wanted to keep any of the topics discussed hidden, Cummings said. In 2016, President Trump berated Hillary Clinton for using a private server while secretary of state, and continues to bring it up at his rallies.