The primary sub-source that former British spy Christopher Steele used to compile his anti-Trump dossier in 2016 was the subject of an FBI counterintelligence investigation a decade ago, according to details authorized for release by U.S. Attorney John Durham, who is investigating the origins of the FBI’s Trump-Russia probe.

Allies of President Donald Trump have speculated for months that Durham’s review, ordered by Attorney General William Barr, will end with top Obama-era officials in handcuffs. They have cast the Russia investigation as fundamentally illegitimate, arguing that surveillance warrants that drew on the so-called Steele dossier discredit the probe as a whole.

But the Connecticut-based prosecutor’s decision to release evidence connected to his examination of Steele dossier suggests it is highly unlikely he intends to issue criminal indictments related to that aspect of his review.