The plan was simple: knock on Sogen Kato's front door, congratulate him on his longevity, offer a cash reward and inquire whether Tokyo's oldest resident would, at the age of 111, mind taking part in Japan's "Respect the Elderly" festivities on September 20.

After a bit of doorstep argy-bargy with his 81-year old daughter, the authorities were led upstairs to Kato's bedroom. He was there all right. Or, at least, his bones were: swaddled in bandages and surrounded by newspapers from October 1978, the last time he had drawn breath or followed world affairs.

At first, the reaction of officials was bafflement. The records showed Kato as a punctilious form-filler, a clockwork casher of his monthly pension cheques and, critically, alive.

Soon a ghastly truth dawned: first on Adachi ward in which he lived, then on Tokyo, then on Japan as a whole. It was not just that Kato had been a mummified skeleton for 32 years, or that he had, apparently, starved himself to death as a "living Buddha", or that his surviving family (later arrested) had illegally pocketed £70,000 of pension payments. It was that official records - and the Japanese - were not to be trusted. Few blows to national psyche could be as violent. The discovery of Kato has plunged Japan into perhaps its greatest crisis of confidence for decades: a nation that prides itself on precision, honesty and orderliness has found itself in a tangle of slapdash, dysfunction and fraud.

The Adachi ward officials set about assuring themselves this was a one-off incident and went to check on 113-year- old Fusa Furuya, Tokyo's oldest woman. A doorstep discussion with an ageing daughter revealed that, despite what the records showed, Fusa Furuya had not been seen at the house for 50 years. An alternative address given to police turned out to be a car park.

Japan started to wonder about its 41,000 centenarians. Anomalies began appearing everywhere: Aichi prefecture found it had a woman on its books who was officially alive at the age of 142. In Osaka, more than 5,100 people aged over 120 are "missing" - officially alive, but almost certainly dead.

As the formal search began, the findings made it worse. There was the discovery that Kikue Mitsuishi, registered as 104 and another pension claimer, had resided (cleaned and crushed) in her son's rucksack for more than a decade. He had, of course spent the £1,000 annual cash gifts paid to the super-old.

David Fuller's view This macabre story would be amusing if it were not so sad. It also testimony to the extent to which once heralded economic governance can decline.

When I traveled to Japan from 1987 to 1989, its people were the world's number 1 consumers and had the highest standard of living, at least on paper. Today, Japan seems rudderless, although it still has a number of world-class export companies. Unfortunately, they are suffering from a too strong yen and the incumbent prime minister, who is likely to survive this week's challenge, has so far shown little interest in doing anything about it.