Danish police believe the theft of  a necklace that was recovered from the Titanic wreckage was part of an “inside job.”

The necklace was discovered missing from a showcase at  Copenhagen’s Tivoli Gardens amusement park Saturday morning.

“The showcase has not been broken into and the alarm didn’t go off,” spokesman Torben Planks told the Associated Press. “It’s pretty embarrassing.”

“It was a very important piece. The artifacts tell stories about the people aboard,” exhibition owner Luis Ferreiro told the AP.

He also said that the gold-plated necklace was unlikely to be sold because it is so well-known internationally.

Valued at $19,300, the necklace was on show as part of a traveling exhibition of expensive trinkets that sank with the “unsinkable” Titanic in the early morning hours of April 15, 1912.

The piece was originally owned by first class passenger Eleanor Wildener, a Philadelphia woman. She survived the disaster, which killed 1,517 people.

Tivoli Gardens, located in Copenhagen, Denmark, is the second oldest amusement park and fairground in Europe. It opened to the public on August 15, 1843.