BRUSSELS — A shipment of a quarter million AstraZeneca vaccines destined for Australia has been barred from leaving the European Union in the first use of an export control system.

An EU official, who asked not to be identified because of the sensitivity of the issue, confirmed a report that first appeared in the Financial Times. The move came at the behest of Italy, which has been taking a tough line in dealing with vaccine shortages within the 27-nation bloc since a new government led by Mario Draghi came into power last month.

Faced with shortages of doses during the early stages of the vaccine campaign that started in late December, the EU issued an export control system for COVID-19 vaccines. It requires companies respect their contractual obligations to the bloc before commercial exports can be approved. So far, the EU has vaccinated only 8 % percent of its population.