The Russian women's 4x400m relay team have been stripped of the silver medals they won at the London 2012 Olympics after Antonina Krivoshapka tested positive for a banned substance.

Krivoshapka has been disqualified from the Games five years ago after dehydrochlormethyltestosterone (turinabol) was traced when her sample was reanalysed.

Yulia Gushchina, Tatyana Firova and Natalya Antyukh will also forfeit the medals they won in London due to Krivoshapka's failed test.

Gushchina had to hand back the 4x100m relay gold and 4x400m silver medals she was presented with at the 2008 Beijing Games, while Firova was also part of the 4x400 team in China who were disqualified after Anastasia Kapachinskaya tested positive for a steroid.

Krivoshapka, who won relay gold at the 2013 World Championships in Moscow, finished 6th in the 400m final at the London Games but that result will not stand.

The International Olympic Committee also revealed that Turkish boxer Adem Kilicci, who was fifth in the 69-75 kg category, has been disqualified from the London Olympics after he tested positive for the same substance as Krivoshapka.

Russian discus thrower Vera Ganeeva also tested positive for dehydrochloromethyltestosterone (turinabol).