The doctor of the Warriors rugby league team is claiming many top players are abusing prescription drugs.
John Mayhew claims on the ABC'S 7.30 programme on Tuesday night were followed on Wednesday by the National Rugby League announcing it will begin testing players for two classes of prescription drugs.
The NRL said it will test this season for benzodiazepines such as valium and mogadon and for zopidems such as the sleeping pill, stilnox.
However, it said it only wants to find out if there is abuse and only has rumours to go on before deciding whether to impose sanctions next season in 2015.
But Dr Mayhew told the ABC that players are abusing the drugs to get a high without contravening any of the sports existing drug testing protocols.
"I believe the problem is quite prevalent in the NRL of the mixing of stilnox, benzodiazepines with alcohol and caffeinated drinks," he said.
"He's been told this by players taking the drugs and some that know of others taking the drug. This is not just a New Zealand scenario, it's in Australia."
League organisers blamed the same sort of drug mixing for the poor performance of New Zealand's national side, named the Kiwis, in the final of the World Cup in England last year. They lost the final of the tournament 34-2 to Australia.
New Zealand Rugby League changed its rules following the tournament and its High Performance Manager Tony Iro said he's pleased the NRL in Australia is now adopting testing.
"We've expanded our code of conduct. We do have the right now to test for prescription medication and any action from that will be at our discretion," he said.
But the drugs are not illegal under the World Anti Doping Agency rules. And Mr Iro said that makes it unclear just what punishments could be handed down.
John Mayhew, who has also been the All Black's doctor, said it's not just rugby league where drug abuse was happening.
"I think it's a problem in the NRL. I've had discussions with people in other codes and it's a problem in other codes," he said.
The New Zealand Rugby Union is investigating reports of Super Rugby players doing the same thing. It said it's asking sports doctors to tell it what they know of any such abuse.