Russian distance runner Liliya Shobukhova has had her doping ban reduced by the World Anti-Doping Agency, meaning that she is now free to compete.
The 37-year-old, who won the London Marathon in 2010, was initially handed a 38-month suspension due to abnormal findings in her biological passport.
However, after assisting WADA in other doping investigations, Shobukhova's ban was cut to 31 months.
A statement from WADA read: "The information and documentation provided has been of substantial value in uncovering and investigating anti-doping rule violations committed by other individuals, including athlete support personnel."
The Russian athlete was stripped of her 2009, 2010 and 2011 Chicago Marathon victories.
