Maybe not the one you're thinking, but this is notable recent case: https://en.wikipedia.org/wiki/Salvator_Mundi_(Leonardo) https://en.wikipedia.org/wiki/Salvat

Maybe not the one you're thinking, but this is notable recent case: https://en.wikipedia.org/wiki/Salvator_Mundi_(Leonardo) https://en.wikipedia.org/wiki/Salvator_Mundi_(Leonardo) The attribution to Leonardo is extremely dubious, but the whole thing seems to have been motivated as yet another attempt to wash the reputation of oil theocracies and their monarchs.