The spokesman said a criminal investigation was under way but declined to comment further, the Houston Chronicle reported Thursday.
The Smoking Gun website reported a hacker compromised emails, phone numbers and street addresses for many Bush family members, including the two former presidents. The hacker also accessed several photographs, including at least one taken of George H. W. Bush during his recent hospitalization in Houston.
The photos and emails were uploaded Wednesday to an online account, Smoking Gun said.
The hacked emails indicated Bush's health was so tenuous in late December that the former president's chief of staff notified the children that their father's "funeral team is having an emergency meeting ... just to go through all the details," the Smoking Gun said.
The hacker, who was not identified, told the Smoking Gun federal officials began investigating him a "long time ago" and that he has breached "hundreds of accounts."