The Russian, the second fastest women's marathon runner in history before her performances were annulled, had been banned for three years, two months following the discovery of “abnormalities” in her Athlete Biological Passport (ABP).

The final seven months of her suspension have been commuted, however, after she offered "substantial assistance" to the World Anti-Doping Agency (WADA), who are investigating allegations of systematic doping in athletics in Russia.

It means her ban officially ended on Sunday (August 23) and she is free to compete again. 

Bitel has claimed, however, that lifting the suspension early breaks IAAF Rule 40 (12) which states that as a condition to regaining eligibility an athlete “must repay any and all prize money that he has received in relation to performances in competitions” from the date of the first adverse doping finding.

Officials from the Chicago and London Marathon revealed earlier this month they are taking legal action against Shobukhova after it was estimated that she won more than $1.5 million (£1 million/€1.4 million) in prize money in the period 2009 to 2011, including a $1 million (£650,000/€900,000) bonus as winner of the World Marathon Majors Series in 2009-2010.

During that period she had won every Chicago Marathon between 2009 and 2011 and the London Marathon in 2010 and 2011. 

"We believe there should be no place in our sport for people who have cheated, no matter how much assistance they give after they have been caught, and that they need to repay all money earned so that clean athletes can benefit," Bitel, one of Europe's top sports lawyers currently in Beijing attending the IAAF World Championships, said. 

"The London Marathon supports IAAF Rule 40 which makes a banned athlete ineligible to take part in the sport until they have repaid all forfeited prize money and believes that this should be strictly enforced in all cases.

“We are determined to make marathon running a safe haven from doping.

"This means that cheats should not be permitted to keep their ill-gotten gains under any circumstances.

"The London Marathon’s zero tolerance policy towards doping is unaltered.

"Shobukhova is still banned for life from taking part in the London Marathon and in any of the five other marathons that make up the Abbott World Marathon Majors.

"The London Marathon has already announced that it will commence legal proceedings against athletes who have failed tests if they do not repay money that they have received from the event and has already taken steps to do so in the case of Shobukhova."

Related stories
August 2015: Disgraced London and Chicago Marathon champion has drugs ban lifted early and is free to compete
August 2015: London Marathon to take banned Russian to court over prize and appearance money
February 2015: "Integrity" key as World Marathon Majors announces unprecedented anti-doping and prize money format
February 2015: Russian Athletics President to resign over doping scandals
January 2015: WADA Commission to complete investigation of athletics doping allegations by end of year