Cape Town - New Zealand Rugby (NZR) is confident doping is not systemic in the sport but says any future breaches have the potential to "darken the image of players who have gone before them in the black jersey".
This comes after it was revealed earlier this month that four New Zealand rugby players had been suspended for doping offences.
Glen Robertson, a former New Zealand under-20 and sevens international and female player Zoe Berry, who played one Test for the Black Ferns against England in 2012, were both given four-year suspensions.
Two other club-level players received a two-year ban and a 21-month ban respectively.
Rhys Pedersen, Berry and Robertson were banned for possessing and in some cases using or attempting to use stimulant clenbuterol, while Ben Qauqau-Dodds was charged with possession and use or attempted use of anabolic steroid metandienone.
In an interview with NewstalkZB over the weekend, Neil Sorensen, NZR's general manager, said the issue could be "incredibly damaging".
Sorensen said Drug Free Sport New Zealand (DFSNZ) had told the NZR to expect more doping charges against Kiwi rugby players.
"It's massively disappointing. We knew it was coming as Drug Free Sport gave us a heads up some time ago that it was coming. We've been told there are more (rugby players) to follow,” Sorensen was quoted as saying on the Stuff.co.nz website.
The NZR had not been told what level the players were involved in because the DFSNZ inquiries were confidential, he added.
"We are pretty confident - though I can't say that with total belief - we are not going to be talking about Super Rugby players, All Blacks or Black Ferns.
"Then again Zoey was a Black Fern back in 2012 and the (drug) education that she received obviously didn't get through."
Sorensen said it could be "incredibly damaging" to New Zealand rugby's international media image if a high profile player was involved.