Chinada determined the swimmers had unintentionally ingested the substance because of contamination.
The case has drawn criticism from athletes and the United States Anti-Doping Agency (Usada), whose chief executive Travis Tygart suggested a cover-up – a claim Wada rejected as “completely false and defamatory”.
The IOC, however, has called for all “stakeholders” to respect Wada’s “supreme authority” in the fight against doping.
“This respect forms the basis on which Wada was founded by the governments of the world and the Olympic Movement,” the IOC said.
“This respect is essential for any fair international competition.”
Cottier’s full report is expected in the coming weeks.
The US Department of Justice (DOJ) is also investigating the case, which Wada said on Thursday it was “disappointed” to learn.