The treasure hunt comes after he defaulted on a court judgment ordering him to pay the internet company $12.8 million (£6.7 million) in damages for flooding its members with unwanted e-mail adverts. The spammer has now disappeared.

Davis Wolfgang Hawke, a former neo-Nazi, and his partners made up to $600,000 (£315,000) a month from unsolicited advertisements for pornography, weight-loss tablets, mortgages and penis- enlargement pills.

AOL says that it has receipts showing that Mr Hawke, 28, bought bars of gold and platinum with his profits, and it wants to find them. The company believes that he buried the ingots in the two-acre garden of his parents’ home, 20 miles southwest of Boston, which was his last known address.

“I don’t care if they dig up the entire yard. They’re just going to make fools of themselves,” Peggy Greenbaum, his mother, said. “There’s absolutely no reason for them to think that Davis Hawke would be stupid enough to bury gold on our property. My son is long gone.”

The spammer allegedly told his family that he bought gold instead of homes and cars because it would be easier to hide in case of a lawsuit. The family believes that he may have buried gold near to ski resorts in the White Mountains of New Hampshire.

“He told us he was going to hide his assets and disappear, and he appears to have done that,” Hyman Greenbaum, his father, said.

AOL has already seized $20,000 (£10,500) in gold, $75,000 in cash and a Hummer H2 car with the numberplate “CASHOLA” from Mr Hawke’s partner, Braden Bourneval, 21, a New Hampshire chess champion who settled with the company. It gave the assets away to its internet subscribers in online sweepstakes.

AOL believes that Mr Hawke and Mr Bourneval were responsible for billions of e-mails that clogged its members’ inboxes. A total of 130,000 AOL customers complained, allowing the company to obtain $100 per complaint in damages when Mr Hawke failed to appear in court.

“The dig isn’t something out of Treasure Island,” Nicholas Graham, an AOL spokesman, said. “This is a court-directed, judge-approved legal process that is aimed at responsibly recovering hidden assets.”

Mr Hawke, born Andrew Britt Greenbaum, set up a neo-Nazi group as a teenager and once appeared on television in a military uniform vowing to “make the Final Solution a reality”. But he was shunned by other white supremacists when they discovered that his father was part-Jewish.

Mr Greenbaum says that he last spoke to his son last year. “If they find something on my property and they can’t prove that it belongs to my son, then by default it belongs to me. So if they hit oil, I’ll put up a gas station or something.”

JUNK MAIL DELUGE THAT COSTS BILLIONS

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