MADRID, Spain — Spanish authorities searched a state-funded research laboratory near Barcelona on Thursday amid an investigation into the region’s African swine fever outbreak, regional police said.

The court-ordered search targets the Centre for Research in Animal Health (Cresa) and comes after genome sequencing revealed that the virus strain in wild boars closely matches those used in research and vaccine development, unlike other European cases, Reuters reported. Police said the investigation is part of preliminary proceedings declared secret by a local judge.

African swine fever does not affect humans but is highly lethal to pigs and wild boars and spreads rapidly. Spain, the European Union’s largest pork producer, accounting for roughly a quarter of the bloc’s output, has imposed movement restrictions and increased measures to reassure trading partners as the outbreak threatens exports.

Authorities have so far found the virus in 26 wild boar carcasses in the six-kilometer confinement area established near the Collserola hills outside Barcelona, where the outbreak has been confined to wild animals, with no farm cases reported. Cresa, located within the restricted area, told Maldita.es that it had found no evidence linking it to the outbreak and did not immediately respond to a separate request for comment.