A hacker who breached the communications service used by former Trump national security adviser Mike Waltz earlier this month intercepted messages from a broader swathe of American officials than has previously been reported, according to a Reuters review, potentially raising the stakes of a breach that has already drawn questions about data security in the Trump administration.

Reuters identified more than 60 unique government users of the messaging platform TeleMessage in a cache of leaked data provided by Distributed Denial of Secrets, a U.S. nonprofit whose stated mission is to archive hacked and leaked documents in the public interest. The trove included material from disaster responders, customs officials, several U.S. diplomatic staffers, at least one White House staffer and members of the Secret Service. The messages reviewed by Reuters covered a roughly day-long period of time ending on May 4, and many of them were fragmentary.

While Reuters could not verify the entire contents of the TeleMessage trove, in more than half a dozen cases the news agency was able to establish that the phone numbers in the leaked data were correctly attributed to their owners. One of the intercepted texts’ recipients - an applicant for aid from the Federal Emergency Management Agency - confirmed to Reuters that the leaked message was authentic; a financial services firm whose messages were similarly intercepted also confirmed their authenticity.