Swimming's world governing body Fina and the World Anti-Doping Agency (Wada) are investigating claims of anti-doping violations by Chinese competitors.
A report in The Times claimed five positive tests by Chinese swimmers had been covered up.
Fina has confirmed it is deciding whether any of the allegations require further investigation.
A Wada spokesman said it is looking at information provided by the Times "to address this matter head on".
|Drug-testing in swimming - the numbers|
|Fina carried out 1,094 out-of-competition tests on 654 athletes in 2015|
|It also carried out 815 in-competition tests on 569 athletes last year|
|Fina spent £560,000 on anti-doping in 2015 - approximately one tenth of the figure that cycling's governing body, the UCI, spent|
A Fina statement read: "There are a small number of cases of failed doping controls by Chinese swimmers currently being investigated under the jurisdiction of Chinada, the Wada-recognised Chinese Anti-Doping Agency.
"Fina and Wada are both fully aware of these cases, but we are bound by confidentiality until the moment an athlete is actually banned.
"If the information we receive does merit further investigation, then Fina will leave no stone unturned in ensuring justice is served for the overwhelming majority of aquatics athletes who are clean."
It comes after Wada said on Wednesday it would investigate allegations of systematic doping in Russian swimming.
The Times had said it had "evidence of an organised drugs culture" similar to the one in Russian athletics but Fina said they were "not aware" of any "concrete evidence of systemic doping".