World champion swimmer Yuliya Efimova will appeal to the Court of Arbitration for Sport (CAS) after the International Olympic Committee's deal with Russia ruled her out of Rio 2016.

The IOC refused to issue Russian competitors with a blanket ban over two damning independent reports requested by WADA revealed the extent of state-sponsored doping and the means to cover it up.

Individual sports' governing bodies have been left with the task of determining if Russian individuals are fit to compete, however any competitor from Russia to have previously been sanctioned for doping offences is automatically ruled ineligible.

This is not consistent across all nationalities. For example, Justin Gatlin of the United States is set to be one of the headline competitors in the 100 metres despite two doping violations in his career.

Such a double standard has not been lost on athletes or pundits alike, with Efimova's appeal potentially the first of several.

"We are preparing Efimova's lawsuit which will most likely be filed at CAS on July 29," her attorney Artyom Patsev told TASS.

A four-time world champion specialising in breaststroke, Efimova tested positive for DHEA in 2014, subsequently having 16 months' worth of results expunged before returning to action at the 2015 World Championships and winning gold in the 100m breaststroke.