The IOC opened an ethics investigation last month after Britain's Sunday Times newspaper reported that national Olympic committee officials and ticket agents in several countries were willing to offer tickets on the black market.
The paper turned its evidence over to the IOC, which was still reviewing it.
The evidence was a "huge file," IOC President Jacques Rogge said Saturday, and a decision would likely take months.
"(There is) more than 20 people involved and a lot or organizations and commercial ticket resellers," Rogge said. "The rights of the defence require everyone has the chance to explain his or her case. We expect the results of that probably by the end of September, beginning of October, because it is a huge work."
The IOC could have provisionally suspended any implicated officials or barred them from attending the games but the IOC executive board decided against that because hearings would still take some time.