Nickelodeon What happened to the SpongeBob coins? Some 76 sets of silver coins with the image of cartoon character SpongeBob SquarePants have vanished from now-defunct financial firm Peregrine, according to a trustee's filing.

CHICAGO - When Peregrine Financial Group collapsed in July after revelations its chief executive allegedly stole client money for years, it was not just customer assets of the futures brokerage that went missing.

Some 76 sets of silver coins sporting the image of cartoon character SpongeBob SquarePants were also unaccounted for, according to a note buried deep in a filing by Peregrine Financial's bankruptcy trustee late Thursday. Thirty-nine ounces of gold were also missing.

At Friday's prices, the gold would fetch about $66,000; the missing commemorative SpongeBob coin sets, minted in New Zealand, have a total retail value of about $20,000.

Compared with the $215 million in customer money that regulators allege were wrongly siphoned from the firm by its CEO, Russell Wasendorf Sr., the value of the missing metals is marginal.

But the filing, which provides rich details on all of Peregrine Financial's known assets, down to a decade-old Apple Inc computer valued at $5 -- leaves open the possibility that Peregrine itself may have been the victim of pilfering.

Or a few valuable items that were misplaced.

Shortly after Wasendorf attempted suicide on July 9, leaving a signed confession of his years-long fraud, the FBI searched the firm's Cedar Falls, Iowa, headquarters and seized a stash of SpongeBob coin worth about $375,000, based on the retail price per set of $259.

Peregrine owns 1,528 sets, according to the bankruptcy court filing's 180-page document that lists assets and some liabilities.

A note added, "2 sets were located in Iowa desks, 1 set is held by Tom Garland in Chicago, and FBI inventoried 1449 sets; so PFG is missing 76 sets."

Garland was the firm's director of precious metals.

The list said Peregrine also owned 172 ounces of gold, but only 133 ounces could be located, according to the filing, which also provided the first details on Peregrine assets and debts since the firm filed for bankruptcy on July 10.

"39 ounces missing," it said.

SpongeBob SquarePants is a cartoon series on the Nickelodeon cable television network, a unit of Viacom Inc.

More money and business news:

Follow NBCNews.com business on Twitter and Facebook