More than 230,000 Japanese citizens listed in government records as at least 100 years old can't be found and may have died long ago, according to a government survey released Friday.
In August, the Justice Ministry ordered a review of records that found about 77,000 people who would be at least 120, and 884 people who would be 150 or older.
The head count followed a flurry of reports about how elderly people are falling through the cracks in Japan as its population ages rapidly and family ties weaken.
In all, the survey of family registration records nationwide found that 234,354 centenarians were still listed as alive, but their whereabouts were unknown, the ministry said.
Because listings of people over 120 are almost certainly the result of lax bookkeeping, the ministry instructed local offices to attach a note to those records saying the people were unaccounted for, a ministry official said.
A ministry official said many of the missing people had probably died, lost touch with relatives or moved overseas. The official spoke on condition of anonymity, citing ministry policy.
In late July, police discovered that Sogen Kato, who would have been 111 and was thought to be Tokyo's oldest man, had actually been dead for 32 years, and his decayed body was still lying in his home.
Police have arrested his granddaughter for suspected abandonment and pension fraud.
That case and other revelations of scamming relatives and isolated and forgotten elderly people led to closer scrutiny ahead of the Health Ministry's annual report on centenarians.
An official at the Health Ministry's statistics bureau said Friday's survey does not change Japan's status as a fast-aging nation because life expectancy calculations are not based on family registration records.