A ruling by the EU's top court has dealt a further blow to Italy's attempts to create a fast-track system in Albania for processing asylum applications offshore.

Europe's top court on Friday questioned the legitimacy of the "safe countries" list Italy uses to send migrants to Albania and fast-track their asylum claims, in a fresh blow to a key plank of the government's migration policy.

The specific case that led to the ECJ's opinion involved two Bangladeshi nationals who were rescued at sea by Italian authorities and taken to Italy's detention centre in Albania,