A variant composition, showing Prometheus in a slightly different position and with the group placed within a horizontal oval, is recorded in a drawing in the Victorian and Albert Museum, London. Ward-Jackson records two further versions of the London drawing: one formerly in the collection of George Knapton, which is engraved in Roger´s Imitations of Old Master Drawings (1778); and another on the art market, New York, in 1961.

Turner, Nicholas, From Michelangelo to Annibale Carracc: a century of Italian drawings from the Prado, Virginia, Art Services International, 2008, p.268