A German court has sentenced a former technician at the Deutsches Museum in Munich to prison for stealing and selling artwork to fund his lavish lifestyle. The unnamed man, now aged 30, used the money from the audacious thefts to pay off debts as well as buy a new apartment, expensive watches, and a Rolls Royce.

“The accused shamelessly exploited his access to the depots in his employer’s premises and sold valuable cultural property to secure himself an exclusive standard of living and to boast about it,” the court said in a statement.

The Deutsches Museum is one of the biggest science and technology institutes in the world. Unrelated to its main collection, the museum also owns a collection of paintings that were primarily acquired through bequests. Hundreds of these valuable artworks are stored in a depot where only staff can access them. As part of his job, the defendant was given regular access to the depot when he was employed by the museum from May 2016 to April 2018.

In one instance, he swapped The Fairy Tale of the Frog King by Franz von Stuck (1863-1928) with a forged copy before selling the original for more than €49,000 (£42,000) at Ketterer Kunst auction house. To conceal his crimes, the man pretended the painting was an heirloom from his great-grandparents. Through the same auction house, he also sold Eduard von Grützner’s (1846-1925) The Wine Tasting for almost €4,500 (£3,900) and Franz von Defregger’s (1835-1921) Two Girls Collecting Wood in the Mountains for €7,000 (£6,000). A fourth painting failed to find a buyer.

“We have, of course, fulfilled our duty of care in full and have researched the works mentioned extensively,” commented a spokesperson for Ketterer Kunst. “We regret that the works were stolen from the museum with such high criminal energy. We cooperated closely with the LKA (Bavarian State Criminal Police Office) at an early stage and handed over all documents to solve this case.”

A provenance researcher at the museum eventually noticed that the fake painting, despite being in the right frame, was in fact “quite a clumsy copy”. The other three paintings were stolen and never replaced, leaving empty frames behind in the depot.

The defendant has received a suspended sentence of one year and nine months in prison and ordered to pay back damages of more than €60,000 (£52,000) to the museum. Judge Erlacher of the district court in Munich gave a relatively lenient sentence because he had no prior criminal record and had expressed some regret for the crimes committed several years ago. Reflecting on the crimes, a museum spokesperson, Sabine Pelgjer, said “there was no way of knowing he was capable of this when we hired him. We actually do have pretty secure facilities, but when it is one of your own employees, it’s pretty hard to keep safe.”