The IAAF, the governing body for athletics, said that six of the nine athletes had been caught through the athlete biological passport scheme, which will be used at the Olympics for the first time this year.
The other three positive doping results were retested samples from last year's world championships at Daegu, South Korea.
The athletes were guilty of "sophisticated doping," the IAAF said, and received bans ranging from two to four years.
"Today's announcements underline the IAAF's continued and unwavering campaign against doping in athletics," IAAF President Lamine Diack said in a statement. "We will not stint in our resolve to do everything in our power to eradicate cheating."
The biological passport measures changes in an athlete's blood profile and is already used in professional cycling. It will be utilized in testing in track and field, swimming, cycling, rowing, modern pentathlon and triathlon at the Olympics, the World Anti-Doping Agency announced in a news conference at Olympic Park.
WADA also said a new test for the abuse of human growth hormone would be used at the games, just weeks after it was cleared following a near 13-year development process.
One of the athletes sanctioned by the IAAF from the world championships — sprinter Inna Eftimova of Bulgaria — was guilty of using synthetic human growth hormone.
HGH abuse has been hard for the IAAF and other sporting bodies to test for and is among the three biggest doping worries for the London Games, according to WADA, alongside the blood booster EPO and synthetic testosterone use.
The first HGH test at the Olympics was in Athens in 2004. This year, American weightlifter Pat Mendes — the top-ranked lifter in his country in the over-105-kilogram weight class — became the first U.S. athlete in an Olympic sport to test positive for HGH and be disciplined for it. He was banned for two years in April.
WADA director general David Howman said the new HGH test would work alongside the old one in London, giving testers a larger window to find traces of the substance.
"It's in place," Howman said. "The marker test, which is a new test for human growth hormone, is in place and can be used by the laboratory during the games. It's something that underwent a strong period of scrutiny."
WADA President John Fahey said it was "good to see" that the IOC and local organizing committee had decided to use the biological passport in the six sports at the Olympics.
"It is spreading as a tool ... and we've also seen sanctions as a result," Fahey said.
WADA said this week that 107 athletes in Summer Olympics sports had been guilty of doping offences in the six month period up to mid-June.
That number would increase with the cases announced by the IAAF, which included Moroccan, Turkish, Greek, Ukrainian and Russian athletes alongside the Bulgarian. The IAAF on Wednesday also provisionally suspended Moroccan 1,500-meter runner Mariem Alaoui Selsouli from the London Olympics after she tested positive for a diuretic. There's been no announcement over Selsouli's 'B' sample test.
And the IOC is investigating up to five suspicious test results from the Olympics in Athens eight years ago, although time is running out for it to act on those.
Athlete samples can be retested up to eight years after an Olympics ends, leading to possible retroactive sanctions. The statute of limitations from Athens expires on Aug. 29.
The Olympic body's anti-doping chief acknowledged Wednesday he could have acted sooner to retest the samples after an unusual rebuke from a colleague at the IOC's general assembly in London.
Arne Ljungqvist, the chairman of the IOC medical commission, was sharply criticized by former WADA head and current IOC member Dick Pound for only deciding in May to test around 100 samples from Athens.
"The keeping of samples was meant to be a major deterrent," Pound said. "If those we hope to deter understand we do nothing, there is not going to be much of a deterrent."
While WADA hoped for the cleanest Olympics ever in London after carrying out over 71,000 doping tests in the six months up to July 19, it made no guarantees.
"You have to ask that to the 10,000 athletes that are here," director general Howman said, "because the responsibility has to be firmly on their shoulders to prove to you and the world that they have come here clean."
Asked what he thought of hopes that it might be the cleanest Olympics, Howman — an experienced anti-doping official — replied: "I'm too much of a cynic."
AP Sports Writer Stephen Wilson contributed to this report.