Russia's women's 4x400metres relay squad has been stripped of a London 2012 Olympic silver medal after Antonina Krivoshapka tested positive, the International Olympic Committee has announced.
The IOC on Wednesday announced three further anti-doping rule violations following re-analysis of samples from Beijing 2008 and London 2012, taking the total to 101.
Krivoshapka tested positive for the steroid turinabol and her sixth-placed finish in the 400m individual event and Russia's second-placed finish in the relay event have been wiped from the record books.
The United States won the relay event and Jamaica finished third, with Ukraine fourth.
Russian discus thrower Vera Ganeeva tested positive for the same substance and her 23rd-placed finish at London 2012 has been expunged from the records.
Turkish boxer Adem Kilicci, who reached the quarter-finals of the middleweight (67-75kg), also tested positive for turinabol and was disqualified.
The three positive tests took the total to 40 adverse findings from 492 samples re-analysed from the London 2012 Olympics.
Of the 1,053 samples re-analysed from the Beijing 2008 Olympics, 61 have been positive to date.