Updated

U.S. Ambassador Stephen Mull has returned to Polish authorities a prisoner's cap from the Nazi death camp of Majdanek that was spotted in an online auction site in the United States, priced at $1,750.

The gray-and-blue striped cap had been stolen from the Majdanek museum, in eastern Poland, before 1995, when visitors had easy access to exhibits.

An anonymous caller notified Polish authorities in June that the cap was on sale. The FBI helped retrieve it, while forensic tests in Poland confirmed that it came from Majdanek.

Mull handed it to Poland's Deputy Culture Minister Malgorzata Omilanowska on Thursday. The cap immediately returns to the museum, which preserves the memory of some 80,000 people, mostly Jews, who died there between 1941 and 1944.