The J. Paul Getty Museum in Los Angeles is returning ancient sculptures and other works of art that were illegally exported from Italy, the museum announced Thursday. The Getty will return a nearly life-size group of Greek terra-cotta sculptures known as “Orpheus and the Sirens,” believed to date from the fourth century B.C., according to the museum.

The sculpture group was purchased by J. Paul Getty in 1976 shortly before his death and had been on display for decades. However, the museum now believes they were illegally excavated and taken out of Italy, based on evidence uncovered by the Manhattan district attorney’s office, the Getty said in a statement.