Spain’s military was deployed on Monday to contain an African swine fever outbreak near Barcelona which officials suspect may have been triggered by a wild boar eating contaminated food such as a sandwich, sparking a chain of events now disrupting the country’s multibillion-euro pork export industry.

Spain confirmed on Friday that two wild boar found dead in Collserola park, 21 km (13.05 miles) from Barcelona, had tested positive for the disease, prompting the establishment of a 6-km exclusion zone around the affected area in Bellaterra. Authorities are currently analysing more suspected cases in the area and expect additional positives.

"The most likely option... is that cold cuts, a sandwich, contaminated food, could end up in a bin – we have to take into account that Bellaterra is an area with a lot of traffic from all over Europe – and then that a wild boar would have eaten it and become infected," Catalonia's agriculture minister Oscar Ordeig told Catalunya Radio on Monday.

African swine fever, while harmless to humans, spreads rapidly among pigs and wild boar, posing a significant economic risk to Spain, one of the world's largest pork exporters.

The infected area is close to the AP-7 highway, a major transport route linking Spain and France. Ordeig said the absence of infected wild boar elsewhere in Catalonia and France suggests human transportation of contaminated food could have introduced the virus.

Efforts to control the outbreak intensified on Sunday, with 300 Catalan police and rural agents deployed, followed by 117 members of Spain's military emergency unit UME on Monday.

Spain's agriculture minister Luis Planas said Saturday that about one-third of the country's pork export certificates have been blocked as a result of the outbreak, though no farms have been affected so far. Pork farms within a 20-km radius of the initial infection site are facing operating and sales restrictions.