The International Weightlifting Federation has suspended 11 athletes - including four Russians - after retested samples returned adverse analytical findings.
Weightlifting's governing body reported that a number of International Olympic Committee reanalyses of samples from the 2012 London Olympics had tested positive, further limiting Russia's ability to send competitors to the Rio Games.
After it was revealed that hundreds of positive drug tests had been covered up by the Moscow anti-doping laboratory under orders from the Russian ministry of sport, each international federation responsible for a sport in Brazil was asked by the IOC to individually vet the anti-doping records of its Russian athletes before clearing them to compete.
The IWF has complied, with Nataliya Zabolotnaya, Svetlana Tzarukaeva, Alexsandr Ivanov and Andrey Demanov emerging as the four Russians to be hit with provisional suspensions ahead of the summer Games, which start on August 5.
Intigam Zairov of Azerbaijan and Armenia's Hripsime Khurshudyan, already suspended following retests of 2008 Beijing samples, were also on a list released by the IWF on Wednesday evening.
Rauli Tsirekidze (Georgia), Almas Uteshov (Kazakhstan), Sibel Simsek (Turkey), Iryna Kulesha (Belarus) and Cristina Iovu (Moldova) complete the group of implicated weightlifters.
The IWF said it was now in a position to "take over the results management of these cases" and that "should it be determined in any of the cases that no anti-doping violation was committed, the relevant decision shall also be published".