Koch said the only way to authenticate these wines is to ask the vintners to vet them, and that, at the very least, the marshals should slap a label on each bottle warning buyers down the line of the Kurniawan connection. He testified at the trial that he had more than 200 bottles he bought from Kurniawan tested for cesium-137, an isotope of the nuclear fallout from the atomic bombs detonated in 1945. He said the tests showed that bottles bearing dates around 1933 or even 1858 carried the isotope, marking them as shams.

To winnow out the impostors from the Kurniawan wines, Michael Egan, an expert who twice helped the government vet them, took a jeweler’s loupe to the oldest and rarest bottles and scrutinized labels to see if they were photocopied fakes, he said. He also evaluated the corks and lead capsules, all marks of Kurniawan’s tradecraft.

Kurniawan mixed Napa Valley pinot noirs with older French wines to make the fakes. In reviewing the stash, Egan discovered a real 1945 Chateau Mouton-Rothschild alongside another that carried a phony label. He believes Kurniawan kept the real bottle to use as a template for his knockoffs.

Interest is strong in the auction’s lower-end bottles, like the case of 2002 Liberty Bay Merlot from Columbia Valley, Washington. Perhaps buyers are betting they’ll enjoy drinking the bargains even if they’re fake -- and maybe never know the difference.

Demand for the higher-end wines Kurniawan liked to fake appeared tepid at first. For days there were no bidders for the ’45 Chateau Mouton-Rothschild, a 750-ml. bottle that bears a “V” for the Allied victory in World War II. Considered one of the greatest wines of the 20th century, it is a centerpiece at high- end auctions. Depending on size and condition, bottles go from $12,000 to $20,000.

This one, marked “faded vintage on cork” and including a nicked label, finally drew an opening bid of $6,375, the minimum, days before the auction of the ’45 Mouton ended, on Tuesday.

“I wouldn’t give you more than $500 if it came from Rudy,” said Joe Palmiotti, co-owner of New York-based Mission Fine Wines, which lost $2 million buying Kurniawan’s faked bottles of the Romanee-Conti. Palmiotti is concerned that buyers are “going to put it right back on the market and likely lie about where it came from.”

In all, the marshals are selling off 4,711 bottles of Kurniawan’s original collection of 5,259.

The long road to the auction started with a pothole. After holding several rounds of bidding for a wine authenticator, the marshals jettisoned their choice after the wine crowd scorned the person’s lack of expertise. This was new territory for the service, which handles about $4 billion a year of assets seized by the government, including art, jewelry and cars, but had never attempted a wine auction on such a grand scale.

Then the marshals had to get the 5,259 bottles shrink- wrapped and shipped in refrigerated trucks from a California warehouse where they had been stored to Pflugerville, Texas, for auctioneers Gaston & Sheehan. Since March, the wine has been stored in a vault at 55 degrees Fahrenheit for the auction house, which has also sold off Bernard Madoff’s vintage watches and Steinway piano.