L'Armoire volante

The aunt of Alfred Puc, a meek tax-collector in Paris, dies while riding in a moving van. The driver, not wishing to be bothered by a police interrogation, hides her corpse in a cupboard before notifying Alfred. But the van is stolen. Alfred, being the heir of a rich lady, begins a frantic search to locate the missing van and the cupboard because one can't claim an inheritance if there is no 'corpus delecti.' (imdb)