In September 11, 2013, four precious golden artifacts from the 10th-century Eastern Medang kingdom period was stolen from the museum. The items were first discovered in the ruins of the Jalatunda ancient royal bathing place and in the temples on the slopes of Mount Penanggungan in Mojokerto Regency, East Java. The four missing artifacts were a dragon-shaped gold plaque, a scripted crescent-shaped gold plaque and one golden-silver Harihara plaque, as well as a small golden box. All the missing items were displayed together in a glass showcase located inside the archaeology gold artifact and treasure room on the second floor of the Gedung Gajah (old wing) building.