Painted just a few weeks before he died — a picture of the doctor who couldn't cure him — Van Gogh's portrait of Dr Gachet was sold one hundred years later for a world record price. The record still stands today — 82.5 million [pounds]. Its sale was the culmination of an extraordinary three-year spending spree in the late 1980s, when art prices more than tripled, thanks mostly, to buyers in Japan.

But when the economic bubble burst, many paintings lost their value dramatically. Loans were called in, and a new phrase entered the art market — Bad Debt Art. The portrait of Dr Gachet came into the possession of a bank. No one knows precisely where it is now.

Impressionist paintings worth US $60 million, which disappeared after they were bought by private Japanese collectors during the economic boom of the late-Eighties, have resurfaced at Sotheby's in New York, where they will be sold on May 10. The sale catalogue, which was issued last week, gives only cryptic clues as to the recent ownership history of the paintings. But they are enough to reignite the curiosity that surrounds the story of Japanese "bad-debt" art.

During the boom years of 1987-1991, approximately $9 billion worth of art was imported into Japan. Assisted by low interest rates, Japanese speculators borrowed heavily against escalating property values to buy at the top end of the market, and then used the art, revalued at an even higher rate, as collateral to borrow again. When the economic crash came in 1991, they, and the art, were caught in a spiral of debt, which is still working itself out.

The subsequent movement of that art has been shrouded in mystery partly because the shame attached to failure in Japanese culture has meant that sales have been conducted as secretly as possible. For Western dealers and auctioneers, there is an added incentive to maintain this secrecy. Bad-debt art was bought at inflated prices, and may be tainted by fear among collectors that the work is still overvalued.

Every picture may tell a story, but the newly hung Renoirs and Monets and Chagalls in Japanese museums record more than rosy flesh or sunsets. Theirs is the tale of the Japanese boom and crash: of the '80s craze for masterpieces among moneyed Japanese, of dashed hopes for the Japanese economy and of '90s debts. During 1990, the peak year of Japan's financial boom, $ 3.3 billion worth of art entered the country, much of it at highly inflated prices. At first banks and other lenders resisted selling, fearing losses. But the Asian financial crisis has meant mounting pressure to get rid of nonperforming loans. The warehouse inventory, said to be worth several billion dollars two years ago, is "shrinking fast," says one banking official.

This "bad-debt art" has democratized the art scene in Japan. More and more masterpieces are emerging from boxes and bubble wrap to end up in public museums.