WASHINGTON, US - The U.S. Army on Friday ordered an investigation into burial and record-keeping mix-ups
at the nation's most venerated war cemetery.

The investigation into Arlington National Cemetery, across the Potomac River from Washington, follows reports suggesting some relatives of the fallen may be paying their respects at the wrong grave sites.

In one case reported by Salon.com, the remains of an Air Force operating room nurse were buried on top of the casket of another deceased service member.

"As the final resting place of our nation's heroes, any questions about the integrity or accountability of its operations should be examined in a manner befitting their service and sacrifice," Secretary of the Army John McHugh said in a statement announcing the probe.

The Army on Friday released the results of an inquiry into another botched burial, revealing that a husband and wife who should have been buried together were buried in adjacent graves - with one of the tombstones left entirely unmarked.

The report suggested the cemetery is under-equipped and under-staffed. Over the past decade, the number of burials at Arlington rose some 20 percent to 4,377 in fiscal year 2008.

Among the most celebrated people buried at Arlington National Cemetery are former President John F. Kennedy and heavyweight boxing champion Joe Louis, who enlisted in the Army during World War II. --REUTERS