Authorities say strain of virus that has killed wild boars in Catalonia is one often used for experiments in secure facilities

Spanish authorities investigating the African swine fever outbreak in Catalonia are looking into the possibility that the disease may have leaked from a research facility and are focusing on five nearby laboratories as potential sources.

Thirteen cases of the fever have been confirmed in wild boars in the countryside outside Barcelona since 28 November, prompting Spain to scramble to contain the outbreak before it becomes a serious threat to its pork export industry, which is worth €8.8bn (£7.7bn) a year.