U.S. Rep. Rick Crawford, the chairman of the House intelligence subcommittee overseeing the Central Intelligence Agency, published an interim report Thursday on an inquiry that began in February into how U.S. intelligence agencies handled the Havana Syndrome—which the government calls “anomalous health incidents.”

“It appears increasingly likely and the Chairman is convinced that a foreign adversary is behind some” of these incidents, the report says. “The Intelligence Community has attempted to thwart the Subcommittee’s investigative efforts to uncover the truth at every turn.”