A Senate sub-committee in the United States has estimated that 6600 graves at Arlington National Cemetery in Virginia may be mislabelled.
At a hearing on Thursday, Senator Claire McCaskill blamed incompetence by cemetery managers.
Former superintendent John Metzler, who was responsible for running the cemetery, where the US has buried its veterans and war dead, accepted full responsibility.
John Metzler said he did not have the resources he needed and has expressed his sincere regrets to the families.
However, Senator McCaskill said he should have brought the problems to Congress or up his chain of command.
The BBC reports an estimated 330,000 people, mostly US military personnel, are buried at the cemetery just outside of Washington.
About 30 funerals per day occur at the cemetery, with 110,000 being buried in the last 19 years.
Among those buried at Arlington are former US President John F Kennedy and his brothers, Robert Kennedy and Edward Kennedy.
Arlington is also the location of America's Tomb of the Unkowns.