However, Dr Gerrard also believes the environment in New Zealand is very different and he would be surprised if there was doping on a similar scale.
The Australian Crime Commission released its findings from a 12-month investigation which said banned drugs were being widely used in Australian professional sport.
The report also found links between some sport and organised crime, which may have led to a case of match-fixing.
As chairman of the World Anti-Doping Agency therapeutic use exemption committee, Dr Gerrard wanted to emphasise he was not speaking on behalf of the organisation but rather as a medical expert with nearly 40 years' experience in anti-doping.
''We need to cast our net to make sure things are in order on this side of the Tasman,'' Dr Gerrard said.
''Having said that, I would like to say that I have every confidence in what Drug Free Sport New Zealand has done in terms of the scope of our out-of-competition testing together with the fact the New Zealand sport science-sports medicine network is a pretty small group.
''I think we would have a fair indication if there were things amiss.
''We're not talking about a bunch of guys who have purchased anabolic steroids on the internet. We're talking about athletes who have been subject to the support of scientists and doctors who know about the procurement of these drugs, their dosage and the form of application.
''You need a sophisticated network and qualified people around you and that is what this report has indicated.''
Drug Free Sport New Zealand chief executive Graeme Steel is of the same mind.
''There are things about our environment which encourage me to think it is less likely to occur here,'' Steel said.
''Most of the doctors of our professional teams are part of the sports medicine community and are well known. The Australian report identifies a decline in the integrity of the sporting environment which we haven't seen here.
''We certainly get very strong support and encouragement from the professional teams in New Zealand. And I suppose the other critical factor is we have fewer people coming in from outside.''
While in Australia the wide-scale doping appears to be restricted to elite athletes participating in major codes, Dr Gerrard feels it is the athletes operating just below that level who are the most susceptible in New Zealand.
An example of that could be a young man striving to make it to the next level who has been told he is too small or not fast enough.
''That's where I think we let our guard down a little. We do extend the education down to that group but we don't engage in enough meaningful testing just because the budget does not allow it.
''It will be interesting to see if Australia extends its anti-doping programme and whether junior players here become subject to greater scrutiny. I think that is the area of greatest vulnerability.''
Younger members of a team or a wider training squad tend to be easier to lead. It is not the 18-year-old fresh out of school who is likely to be the only dissenting voice when the rest of the team is lining up for a jab billed as a vitamin supplement.
''Every athlete must take responsibility for what they are putting into their body. But with the [Lance] Armstrong affair, many of the cyclists were told, you take what you're told or you ship out, because we don't want you on board.
''As a young player, you have an obligation up to a point to do as you are told. This is where the loyalty and the ethics of this whole thing is called into question. That is where these doctors and scientists must be held to account.''