Russian runner Maria Savinova has been stripped of her 2012 Olympic gold medal for doping, putting Caster Semenya in line to take to the title.
Savinova won the women's 800m title at the London Games ahead of South African star Semenya, who went on to capture gold in the same event at the 2016 Olympics in Rio de Janeiro.
The Court of Arbitration for Sport (CAS) says Savinova was "found to have been engaged in using doping" from July 2010 until August 2013.
As a result the 31-year-old has received a four-year ban which has been backdated to August 2015. She has also been stripped of all titles and appearance money won between July 2010 and August 2013.
In 2014, Savinova was caught in undercover footage filmed by Russian doping whistleblower Yulia Stepanova appearing to admit to injecting testosterone and taking the banned steroid oxandrolone.
The footage helped to spark a World Anti-Doping Agency investigation into Russia.
Following further evidence of widespread drug use, the Russian track team was suspended from all international competitions in November 2015.