CLEVELAND (Reuters) - A U.S. judge is keeping a former treasure hunter in jail for again failing to answer questions about the location of 500 commemorative gold coins from the discovery of a 19th century shipwreck, prosecutors said on Monday.

Thomas “Tommy” G. Thompson, 63, of Columbus, Ohio, was arrested in 2015 and jailed because he failed to appear in court to disclose the whereabouts of the gold coins discovered in 1988 in the wreck of the SS Central America.

Last December, Thompson was sentenced to one year of supervised release, a $250,000 fine and 208 hours of community service, but the sentence was not to take effect until he revealed where the coins were.

On Monday, U.S. District Judge Algenon Marbley of Ohio found Thompson in contempt of a court order in a civil lawsuit over the treasure, said Jennifer Thornton, a spokeswoman for the U.S. Attorney’s office in Columbus.

Marbley also continued a daily fine of $1,000 until Thompson reveals the location of the treasure, Thornton said. Thompson’s lawyer could not immediately be reached to comment.

Thompson told the court last December that he had a stroke and suffered from chronic fatigue syndrome, short-term memory loss and other physical problems. He apologized then for not appearing in court previously to answer questions.

Thompson and his former assistant and girlfriend, Alison Antekeier, pleaded guilty last April to criminal contempt after they were arrested in January 2015.

The two had been living in a Florida Hilton hotel under fake names and paying with cash after a 2013 arrest warrant was issued in a civil lawsuit over the proceeds of the shipwreck discovery, which brought up gold coins and bars worth millions.

Members of Thompson’s team and investors had accused him of failing to pay them and they sued.

More than 400 people drowned when the SS Central America, carrying as much as 21 tons of gold from California mines, sank in 1857 off the coast of South Carolina.

Thompson is scheduled to reappear in federal court in Ohio on May 16.