A former British Museum staffer who worked in the prints and drawings department in the 1970s stole more than 350 artworks and sold some of his haul at an antiques market, according to a new book.

As reported by the Independent, “The story of the thefts is recounted in Barnaby Phillips’s forthcoming book, The African Kingdom of Gold—about stolen treasure—and states that Peverett’s thefts were recorded by the museum after they came to light, and an effort was made to recover the stolen artworks.”