5. Giacometti

A damaged plaster sculpture resembling Alberto Giacometti’s early Gazing Head is subjected to provenance research and CT scanning. The initial investigation ends without a firm ruling, but later discovery of a signature leads the Giacometti Foundation to authenticate the sculpture; it subsequently sells for more than half a million pounds. The Giacometti episode was originally intended for Series 6 but was delayed while the foundation continued its examination. It was later rebroadcast with an update after authentication.