HOUSTON ? An old concrete-lined safe that was drilled open after the owner died yielded a treasure trove of what appeared to be gold coins ? but how much they are worth is unknown.

Kese Smith, a spokesman for the Houston Police Department, had no estimate on the coins’ value Wednesday but said it likely involves a “substantial” amount. Officers took temporary custody of the coins earlier this week until parties involved in a civil case that erupted over the safe reached an undisclosed agreement Tuesday, Smith said.

An attorney involved in the matter, Mike DeGeurin, did not immediately return a message seeking comment Wednesday. DeGeurin had said earlier that relatives of the late owner, whose name wasn’t released, apparently gave an individual the safe while clearing the home but said any valuables found were to be returned, according to KTRK-TV.

Locksmith Robert Rivera with Robbie’s Key & Lock Shop says a customer planning to sell the safe for scrap wondered about the contents. Rivera helped with the weekslong effort that ended Monday when the safe was finally cracked open.

“Sometimes it gives up easy; sometimes you’ve got to work at it,” Rivera told KTRK-TV. “I was going to get some C4.”

He was surprised to see boxes of what looked like genuine gold coins. “We thought it was fake, that it couldn’t be real gold,” said Rivera, who contacted police about the find. The locksmith took photos of the contents.

The safe also contained silver bars and jewelry, KPRC-TV reported.

Original article on FoxNews.com