Russian hackers have tracked down Russian runner Yuliya Stepanova.

The whistle blower, now based in the United States, helped uncover the country's state-backed, systemic doping programme.

The information resulted in 118 Russian athletes banned from this year's Olympics, and the whole team banned from the Paralympics.

US correspondent Richard Arnold told Mike Hosking it's grave times for Stepanova.

"Yulia and her family are on the run, they had to flee from their home. They say they are in fear of being murdered."

Richard Arnold said Russian hackers have managed to track her down.

"She kept, as required, an online account with WADA - the World Anti Doping Agency - and that's where the hack has occurred."

LISTEN ABOVE: Richard Arnold speaks to Mike Hosking