Olympic 1,500m champion Rashid Ramzi has been stripped of his gold medal after he tested positive for the banned drug CERA.
Ramzi was one of five individuals from the Beijing Games to fail doping tests earlier this year, when new tests using retroactive blood samples were undertaken.
On Tuesday, Italian cyclist Davide Rebellin was stripped of his silver medal in the Beijing road race for a positive CERA test, Sky Sports informs.
A total of six athletes had initially tested positive for doping after blood sample retests from Beijing were conducted months after the Games.
The athletes all had tested positive for CERA, the new generation of erythropoietin (EPO).
The IOC retested a total of 948 athletes' samples, focusing mainly on endurance events in cycling, rowing, swimming and athletics.
Apart from Ramzi and Rebellin, German Stefan Schumacher, already banned for doping, was also confirmed positive as were Greece's 2004 Athens Games 20km walk champion Athanasia Tsoumeleka and Croatian 800 meters runner Vanja Perisic.
Dominican Republic weightlifter Yudelquis Contreras initially tested positive but was cleared after her B sample came back negative, informs Reuters.
Sebastian Coe, who won two 1,500 Olympic titles and is an IAAF vice president, praised the stripping of Ramzi's medal.
"That was the right decision," Coe said. "Cheats cannot prosper in our sport and people will realize that sooner or later. ... Unfortunately, that was high profile and we can do without it, but it also shows the quality of our testing procedures now."
Asbel Kipruto Kiprop of Kenya stands to be upgraded from silver to gold in the 1,500. Nicolas Willis of New Zealand could go from bronze to silver, and fourth-place finisher Mehdi Baala of France would get the bronze.
The IOC previously disqualified nine athletes for doping at the Beijing Games. They included Ukrainian heptathlete Lyudmila Blonska, who was stripped of her silver medal, and North Korean shooter Kim Jong Su, whose silver and bronze medals were revoked.
A sixth athlete was initially found positive in the retesting process, but women's weightlifter Yudelquis Contreras was cleared by the Dominican Olympic Committee after the "B" sample came back negative, The Associated Press reports.