A final report Thursday confirmed that the World Anti-Doping Agency did not show "favoritism" towards China in the case of 23 Chinese swimmers who were cleared to compete after testing positive for a banned drug.

But it also found WADA's anti-doping rules and administrative processes can be further strengthened, which the agency itself acknowledged.

The report's author, Swiss prosecutor Eric Cottier, said he found "WADA has done its work autonomously, independently and professionally, and that there is no evidence to the contrary."