A California businessman pardoned in 2001 by then-President Bill Clinton must remain in jail on tax-cheating charges until his net worth can be determined, a federal judge ruled.

The Associated Press reported that US Magistrate Judge Andrew Wistrich refused to set bail for Almon Glenn Braswell on Thursday in Los Angeles, saying he will wait until an outside auditor determines his worth.

Prosecutors contend that Braswell, who was arrested last week in Florida, owes $13 million in taxes. He could face up to 51 years in prison if convicted of tax evasion, filing false returns and conspiracy.

They allege that Braswell hid $22 million in earnings in a Bermuda-registered company he controlled.

Assistant US Attorney Paul Rochmes told the judge that Braswell is an extreme flight risk who "has been banking huge amounts of money offshore so that he could run". Braswell's attorney, Gerald Feffer, countered that his client never fled, even though he has known since 1999 that he was under federal investigation.

Braswell has vigorously fought the allegations. Another reason he would not flee is his ongoing custody battle over his 5-year-old son, Feffer said.

Braswell, 59, appeared at the hearing in sweat pants and sporting tinted sunglasses. He runs companies that sell supposed anti-ageing formulas and health supplements touted as helping depression, sexual vitality and prostate health.

His mail-order business, Gero Vita International, lists a return address in Toronto. But company employees are based in Marina del Rey, California and the company's incorporation papers list a Marina del Rey address.

Internal Revenue Service agents took Braswell into custody in Miami on an indictment charging him with evading taxes on $22.2 million in personal income from 1994 to 1997 and skipping corporate taxes by hiding his control of a Bermuda company.

Braswell allegedly inflated business expenses on his returns by marking up prices on raw materials for Gero Vita products by two to ten times through a company he controlled, prosecutors allege.

Braswell spent seven months in prison after a 1993 fraud conviction involving phony claims for a hair-growth product.

Clinton granted 177 pardons and clemencies just before leaving office in 2001. Braswell's pardon became one of the most criticised after it was learned Clinton's brother-in-law had been paid $200,000 for working on the case. Hugh Rodham later returned the money.