But in its judgment in Case C-173/05 Commission v. Italy, the Court of Justice held that a tax imposed by the Sicilian authorities on gas pipelines was a charge having equivalent effect to a customs duty prohibited by Articles 23 and 25 EC.
The local authorities in Sicily instituted a tax on the ownership of gas pipelines that carried gas from Algeria up into mainland Italy. The tax was ostensibly an "environmental tax". The catch in this case was that the tax was payable only when gas actually present in the pipeline. Consequently, the Court held that the Sicilian tax is a charge levied on goods (the gas) imported from a non-member country (Algeria) for distribution and consumption in Italy or in transit to other member States.