Hillary Clinton’s use of a private e-mail server during her State Department tenure emerged as a key campaign issue for Donald Trump, who reveled in the chants of “Lock her up!” that became a defining characteristic of his rallies. And yet, earlier this week, it was revealed that at least six of Trump’s top advisers—Reince Priebus, Steve Bannon, Stephen Miller, Ivanka Trump, Gary Cohn, and Jared Kushner—used private e-mail accounts to conduct government business.

The reports ignited a conflagration of criticism and left Clinton seething at the hypocrisy. But beneath the noise are serious legal questions, some of which concern whether the Trump administration was in violation of the Presidential Records Act. On Friday, Politico reported that the White House counsel’s office has launched an internal investigation into officials’ private e-mail practices.

To date, there has been no public evidence that any of the White House officials exchanged classified information through their personal e-mail accounts—the central charge leveled against Clinton—but the counsel’s office will reportedly be looking to verify this. It will also examine whether White House officials used their private e-mails to discuss the ongoing F.B.I. probe led by special prosecutor Robert Mueller into whether the Trump campaign colluded with the Russian government during the 2016 election.

The e-mail practices of Ivanka Trump and Kushner—who reportedly set up a family e-mail domain shortly before their move from New York to Washington—are of particular interest to the White House counsel’s office, according to two officials who spoke with Politico. The practice has already incited a fresh wave of scrutiny for Kushner, who is a central figure in Mueller’s investigation. After the House Oversight Committee demanded more information about the use of private e-mail accounts in the West Wing, the ranking Democrat on the panel, Elijah Cummings, sent Kushner a separate letter asking him to preserve all the personal e-mails. “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,” the Maryland lawmaker wrote. On Thursday, the Senate Intelligence Committee also asked Kushner’s lawyer to review the top White House adviser’s correspondence, e-mail or otherwise.

Abbe Lowell, Kushner’s attorney, said in a statement that Trump’s son-in-law exchanged fewer than 100 e-mails on the private account and that they have all been forwarded to his White House account. “These usually forwarded news articles or political commentary and most often occurred when someone initiated the exchange by sending an e-mail to his personal rather than his White House address,” Lowell said.