Thompson earlier claimed the coins had been turned over to a trust in Belize - but the government doesn't believe him

Thompson claims he suffers from a rare form of a chronic fatigue syndrome that has created problems with his short-term memory

Has been held in contempt of court since December 2015 for violating a plea deal that required him to answer questions about their location

He is behind bars after allegedly refusing to reveal the location of 500 missing gold coins said to be worth millions

Tommy Thompson discovered the sunken SS Central America - known as the Ship of Gold - in 1988

A former deep sea treasure hunter is allegedly faking memory problems to avoid revealing the location of missing coins minted from gold he discovered in an 1857 shipwreck.

Tommy Thompson rose to fame decades ago when he discovered the sunken SS Central America, better known as the Ship of Gold, in 1988.

But now Thompson - who was on the lam for three years - is behind bars, and allegedly refusing to reveal the location of 500 gold coins said to be worth millions.

Thompson has been held in contempt of court since December 2015 for violating a plea deal in which he was required to answer questions about the coins' location.

Scroll down for video

Former deep sea treasure hunter Tommy Thompson is allegedly faking memory problems so he won't have to reveal the location of missing coins (pictured) he found in a 1988 shipwreck

Thompson has been held in contempt of court since December 2015 for violating a plea deal in which he was required to answer questions about the coins' location

But a federal prosecutor said Thompson's answers were evasive and concerning during the first hearing in October 2015.

At the next hearing, he refused to cooperate at all and a judge also ordered him to pay $1,000 a day until he decides to cooperate.

The former treasure hunter has maintained that he suffers from a rare form of a chronic fatigue syndrome that has created problems with his short-term memory and made it harm for him to provide complete answers.

Thompson also said he could refresh his memory by reviewing documents in 75 boxes held by the US Marshals Service, but that he hadn't been allowed access to that information, according to court records.

But on Thursday a judge ruled that psychiatric evaluations prove that Thompson's isn't suffering from a condition that would prevent him from complying with his plea deal.

A test by a court-ordered psychiatrist turned up minor memory problems, the psychiatrist said in a sealed document, part of which the judge quoted in his order.

Thompson 'routinely made references to things that demonstrated his retention of information from minutes and hours earlier,' the evaluation read.

'He remembered things from one day to the next, he recalled aspects of his various cases with great specificity, and he recalled information about his career and business adventures dating back decades,' it continued.

Thompson previously said that the coins had simply been turned over to a trust in Belize, a claim the government does not believe.

He is now waiting to serve a two-year prison sentence for failing to appear before a judge three years ago to answer questions about the coins.

Thompson rose to fame when he discovered the SS Central America (pictured), better known as the Ship of Gold, which sank off the coast of South Carolina in 1857

Two tons of California Gold Rush gold (pictured) was recovered from the shipwreck. Thompson sold many of the gold bars and coins to a marketing company for $50million

It has been a sharp fall from fame for Thompson, who has since been called one of the 'smartest fugitives ever sought by the US Marshals'.

He evaded law enforcement for three years as more and more problems arose from the discovery of the shipwreck.

It all began when Thompson reportedly sold many of the gold bars and coins to a marketing company for $50million.

The move angered the investors who helped raise $12.7million for Thompson's expedition, who claimed they never saw their cut of profits from the sale.

Thompson failed to appear before a judge in 2012 during the proceedings and a warrant was issued for his arrest.

He and his girlfriend Alison Antekeier wouldn't be spotted again for the next three years.

For more than two years, US marshals in Ohio and Florida worked to track down Thompson.

They did meticulous research, splashed his face on electronic billboards and ran down hundreds of tips from the public.

They found a Vero Beach, Florida mansion Thompson rented between 2006 and 2012, paying the monthly $3,000 rent with cash and putting the utilities in the landlord's name.

The move angered investors who helped raise $12.7m for Thompson's expedition. He then failed to appear before a judge in 2012 during the proceedings and went on the run

Thompson and girlfriend Alison Antekeier (left) were discovered three years later at a Hilton Hotel in Boca Raton and taken into custody

Among the clues: A book called 'How to Live Your Life Invisible' describing how to get by on a cash-only basis, bank wraps for $10,000 and metal pipes that authorities believed were used to store money underground.

Investigators also found 12 active cellphones, each used for specific attorneys or family members.

But there was a trail.

Based on an unspecified lead developed by Ohio agents in December, Florida authorities started focusing on Anteiker.

Then, one day in January 2015, agents spotted Anteiker after fanning out over an area of Palm Beach County.

They tailed her for the next seven hours, watching her use buses and taxis to get to various destinations.

Eventually, Anteiker unknowingly led agents to a Hilton Hotel in suburban Boca Raton area surrounded by golf courses, country clubs and gated communities.

Authorities believe Thompson and Anteiker were living there for up to two years. The room was under one of three fake names being used by Anteiker.

Ted Thomas, Thompson's cousin, said the treasure hunter was driven tofind the shipwreck by his love of science and technology and unattainable feats.

But it ultimately ruined his life.

'If he had to do it all over again, he wouldn't do it,' Thomas said. '