US anti-doping boss takes aim at IOC after 28 Russians have bans overturned

The United States Anti-Doping Agency has launched a strongly-worded attack on the International Olympic Committee after 28 Russian athletes had lifetime doping bans overturned on appeal.

The Court of Arbitration for Sport ruled on Thursday there was "insufficient evidence" to uphold the suspensions issued by the IOC following an investigation into state-sponsored doping at the 2014 Winter Olympics in Sochi.