The NRL's Integrity Unit has requested a copy of the findings of the NZRL's probe into whether Kiwis players misused prescription drugs during the World Cup campaign.
Sunday News last month revealed the New Zealand Rugby League was investigating whether any players combined prescription sleeping pills with energy drinks while in the northern hemisphere late last year.
The combination, which is not illegal, is believed can have the same effects as recreational drugs without breaching the World Anti-Doping Code.
The investigation is expected to be completed later this month and a report to be presented to the NZRL board in February.
Integrity Unit boss Jim Doyle, a former head of the NZRL, has asked for a copy of the report.
Depending on the findings, the Integrity Unit may decide to investigate further. All the players in the Kiwis World Cup squad were registered with NRL clubs, and are under the jurisdiction of the unit.
Past media reports have suggested a number of league players in Australia have used the combination of prescription sleeping pills with energy drinks.
But Doyle said: "I was never aware of this practice when I was at the NZRL.
"We would do a complete SWOT (strengths, weaknesses, opportunities, threats) analysis every time we had a Kiwis camp, whether it was an Anzac test or end-of-season tour. It never came up to my knowledge."
Doyle said after the World Cup he became aware concerns had been raised about the possible use by Kiwis players of the combination during the campaign.
"I was told by quite a few different parties and I got hold of the New Zealand Rugby League and asked them for a report.
"Phil Holden (NZRL CEO) acknowledged to me that he was aware of it and that his organisation was conducting a report that would be presented to the board.
"They will give me a copy of the report when it's finished and we will then have a look at it from there to see whether there is anything else that we should be looking at over and above what they find and what they do.
"I've also asked for a report from the doctor and we'll take things from there.
"Every single player in the Kiwis team was an NRL player so they are 100 per cent under our jurisdiction."
Doyle said he was concerned about the potential impact any misuse of prescription drugs could have on a player's health.
"It's a concern that players may be doing things that affect their health," Doyle said.
"I mean, taking sleeping pills with energy drinks is obviously not normal." Doyle said if any Kiwis were found to have done that, while it did not mean they had acted illegally, they may still have breached their players' agreement with the NZRL.
"The number one priority is the doctor on tour, whether that's the Kiwis or any other team, should be the only person who is prescribing medication or allowing the players to take anything," Doyle said.
"To my knowledge, that's part of the players' agreement that the only supplements they will take are those things provided and approved by the doctor.
"Theoretically, even though it's not illegal, it would be against the policy of the NZRL if the players were taking things that weren't prescribed by the doctor.
"It's for that reason that when I talked to the NZRL I asked for a copy of the report from the doctor." Doyle said the players needed to be aware the policy was in place and that the country could take disciplinary action.
"They may say - we aren't going to pick you again because you aren't following the protocols."
- Sunday News
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