That probe comes in response to reports that a handful of email accounts that include correspondence involving the former president and other family members were exposed by a computer hacker.
The Smoking Gun website said photos and personal correspondence, including emails related to Bush’s recent hospitalisation, were uncovered when the accounts were breached.
“The Secret Service will confirm that it is investigating,” spokesman Brian Leary said. A Bush family spokesman declined to comment.
Among the material that was lifted were a Oct 2012 list of home addresses, mobile phone numbers, and emails for former presidents George HW Bush, George W Bush and other relatives, according to The Smoking Gun.
Separate email accounts used by prominent figures including CBS sportscaster Jim Nantz, a longtime Bush family friend, and others were also breached.
The hacker apparently intercepted photos that former president George W Bush emailed to his sister showing paintings that he was working on, including self-portraits of him showering and in a bathtub, the report said.