Major exploratory research and excavations took place during 1926–1928 by a Soviet team of architects and researchers. During 1937–1939, the Mausoleum was further studied and major restorations works took place under the leadership of B. N. Zasipkin. Graves of three male bodies have been discovered. One of these is identified as Nasr II from the inscription on the lintel; the identity of the other two is not known. During the Soviet era, some time after World War II, the cemetery that surrounded the Mausoleum was paved over, and an amusement park (still in operation) was built next to and around the building.