The Times newspaper reported claims by whistleblowers that five positive tests, two believed to have been failed in October and the others at the turn of the year, were suppressed "to avoid a storm".
WADA, which has already said it will probe earlier claims in the newspaper of 'systematic drug use' in Russian swimming, expressed concern.
"These are very serious allegations concerning Chinese Swimming that warrant further examination," it said in a statement.
"WADA is now fully scrutinising the information that The Times newspaper has passed on to us so that we can determine exactly what the appropriate steps are and so that we can address this matter head on."
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Responding to concerns raised by whistleblowers in The Times report that they could not contact WADA because of "state surveillance", the organisation said it had been working to enhance its whistleblowing process.
"It is our hope that, with an enhanced process, more individuals with high-value information will be willing to come forward, enabling the Agency and its partners to actively pursue anti-doping rule violations that may otherwise go undetected."
China finished second to the United States in the swimming medal table at the 2012 London Olympic Games, and top in the 2014 World Aquatics Championships in Kazan, Russia, with the host nation third.
CLEAN OPPONENTS
Rebecca Adlington, who won the 400 and 800 metres freestyle titles at the 2008 Beijing Olympics, said swimmers at the Rio Games in August needed to be confident they were racing against 'clean' opponents.
"This is a subject that, as a former athlete, I know all about," said the Briton, now retired from competitive swimming.
"We know what it feels like to step up on your blocks at an Olympic Games and look sideways at the other swimmers in the next lanes and be thinking 'are you clean? Are you not? Is something going to come out afterwards?
"Something has to happen," she added. "FINA and the organisers really have to go into it further and have a full-on investigation. That's the only way we are going to be able to say the sport is clean."
An official reached by telephone at the Chinese Swimming Association's news office, who would not give his name, said he was unaware of the newspaper report.
Swimming's world body FINA said on Wednesday that it had asked the Times to share any information about Russian swimmers.
"Any new allegations of doping in our sport, which are substantiated by evidence and which have not already been addressed, will be investigated as a matter of utmost urgency," it added.
The Russian Swimming Federation said it condemned the taking of banned substances and "information regarding the hiding of positive doping tests is completely false."
Russian sport was thrown into turmoil last year when a report by WADA exposed endemic cheating and corruption in Russian athletics.
Russian track and field athletes have been suspended from international competition and will miss the Olympics if the country cannot get the ban overturned, a humiliating blow to the pride and prestige of a sporting superpower.
(Additional reporting by Steve Keating in Toronto, Ben Blanchard in Beijing and Lidia Kelly in Moscow, editing by Ed Osmond)
