https://www.zerohedge.com/news/2018-09-01/russian-oligarch-and-putin-pal-admits-collusion-secret-meetings
The only problem is he didn't collude with Trump. He was asked by Mueller to finance the FBI's mission to rescue retired FBI agent in Iran back in 2009.
(I still believe Hillary killed the negotiation in getting the agent out because either she didn't get her cut of the money, or the retired agent knew something about her and was better left for dead. Maybe both reasons.)