Cyber expert’s arrest silences Russian contacts of some Western crime fighters

Despite acrimonious relations between Russia and the United States in recent years, experts on cyber security in both countries say their law enforcement agencies and private firms had been working together more closely behind the scenes to fight financial fraud and other crimes committed online.

But at least some of that cooperation appears to have come to a sudden halt since Ruslan Stoyanov, head of the computer incidents investigation team at Russian cyber security firm Kaspersky Lab, was arrested in December on suspicion of treason.