Ivanka Trump and her husband Jared Kushner connected their personal email accounts to a server run by the Trump Organization on either Sept. 26 or 27, as their email habits while conducting White House business garnered more scrutiny.

The change was made shortly after special counsel Robert Mueller requested records from the White House for the federal Russia probe.

Kushner's Internet domain was first authenticated in December and mail exchange records for Kushner and Trump's family email domain, ijkfamily.com, show messages were later directed to a Microsoft email system. But the registration was updated in September and now indicates the accounts are connected to two mail servers used by the Trump Organization, according to USA Today.

In response, a spokesperson for Ivanka Trump and Kushner denied these claims.

"Mr. Kushner and Ms. Trump's personal family email account does not reside and has never resided in, nor passed through, the Trump Organization email server," the spokesperson said. "As an additional security measure, this account used a filtering service (to block viruses and malware) as the Trump Organization and lots of other entities and people use. As previously stated, any work-related emails sent to or received from their personal family email account were captured and saved in the White House system for preservation purposes."

Senate leaders have expressed concern that Kushner did not disclose to the Senate Intelligence Committee his use of a personal email account when he met with them during a closed interview.

In response, committee chairman Richard Burr, R-N.C., and committee vice chairman Mark Warner, D-Va., sent a letter to Kushner via his lawyer, Abbe Lowell, demanding Kushner, President Trump's son-in-law, review and ensure he has submitted every relevant document to the committee.

The White House launched an internal investigation of private email use after news broke that members of President Trump's family and several senior White House officials had been using private email accounts to conduct work-related business.

Kushner sent or received approximately 100 work-related emails from his personal account during the first seven months of the year.

Former White House officials were also found to have used private accounts, including former chief White House strategist Steve Bannon and former chief of staff Reince Priebus.