Martin Frankel, the Greenwich, Conn., financier who swindled millions from insurance companies, converted his ill-gotten gains into diamonds before fleeing the country in 1999. He was later captured in Germany, and now about 822 of the gems will be auctioned off next week in New York City to benefit his victims, The Associated Press reports.

Among the items being sold on Monday and Tuesday are a round-cut, 15.67-ct. diamond that is about the size of a nickel and should sell for six figures, the government’s independent appraiser, Ralph S. Joseph, president of The Jewelry Judge of Princeton, reportedly said.

He reportedly said the collection is composed mainly of stones of one to two carats each and includes two dozen flawless gems. The diamonds were shown to reporters at a warehouse on Tuesday.

Neither Joseph nor the Internal Revenue Service, which seized the diamonds, would estimate what the collection might fetch. But the collection is believed to represent the most valuable commodity ever auctioned by the IRS, Agent Steven Hickey of the agency’s criminal investigation unit for New England, reportedly said.

Frankel, 50, pleaded guilty to fraud and racketeering in 2002 and will be sentenced Dec. 10 in New Haven, Conn. He admitted plotting to loot seven insurance companies in five states. The companies had to be liquidated, at a cost of more than $200 million.

He was captured after an international manhunt.

JCK