During the Second World War, Piguet allowed Jewish children to be hidden from the Nazis at the Saint Marguerite Catholic boarding school in Clermont-Ferrand. He was arrested by German police in his Cathedral on 28 May 1944 for the crime of giving aid to a priest wanted by the Gestapo. Imprisoned first in Clermont-Ferrand, he was deported to Dachau concentration camp in September.[2]
At Dachau, Piguet presided over the secret ordination of BlessedKarl Leisner, who died soon after the liberation of the camp.[3][4] He survived his imprisonment, though physically diminished - he had lost 35 kg. He died seven years later.[5]