As many as 2.2 million members of the U.S. Armed Forces may have been also been affected by last month's theft of a Department of Veterans Affairs (VA) laptop.
The data, stolen from an Aspen Hill, Va., home of a VA employee on May 3 also contained the personal information of 26.5 million veterans.
VA and the FBI have launched an investigation into the incident.
VA said this week that the personal information of between 10,000 and 20,000 National Guard and Reserve members, as well as that of 25,000 to 30,000 active-duty Navy personnel may have been affected by the breach.
VA expanded those figures Wednesday to include 1.1 million military members on active duty, 430,000 members of the National Guard and 645,000 members of the Reserves, according to a VA statement.
The personal information of active-duty, National Guard and Reserves members was included in VA files because those servicemen are eligible for certain VA benefits, according to VA.
The department will continue to update the public on future developments, said VA Secretary R. James Nicholson.
"VA remains committed to providing updates on this incident as new information is learned," he said. "The department will continue to make every effort to inform and help protect those potentially affected and is working with the Department of Defense to notify all affected personnel."
Law enforcement agencies have received no indication the stolen information has been used to commit identity theft, according to VA.
Meanwhile, a coalition of veterans groups filed a lawsuit against VA this week, claiming the department did not properly oversee its information.
The complaint was filed by Vietnam Veterans of America, the National Gulf War Resource Center, Radiated Veterans of America, Citizen Soldier and Veterans for Peace.
The suit is seeking an award of $1,000 to every veteran who can prove he or she was affected by the breach as well as an injunction requiring the VA to not change its data storage system until a panel of experts can determine how to prevent future breaches.