Todd Blackadder says he was blindsided by the revelations of widespread doping and corruption in Australian sport.
The former All Blacks captain, who has been involved with the Crusaders for over a decade as a player and head coach, said he had never had any inkling the problems highlighted by the Australian Crimes Commission this week existed.
Blackadder emphasised he believed the Crusaders were a clean organisation.
After learning of the report he said he had held informal discussions with several of the Crusaders management team, including Doctor Deb Robinson - who is also the All Blacks doctor - and was confident any supplements used by his players wouldn't break any laws.
"The guys only take what they are prescribed, so I am pretty sure they are (all clean)," Blackadder said.
"That is why the medical staff take these things so seriously, you have to know what product you are giving the guys because if they are banned substances - well, you should be aware of that."
During his time as an amateur and professional player and coach, Blackadder said he hadn't heard any rumours of doping or corruption in New Zealand rugby.
"In my whole career I have never come across it. I have never been involved with it, I have never heard of it, I have never seen it. I would be really surprised if anyone in New Zealand was involved.
"I am not sure if it is in our nature. The only thing we are involved with in New Zealand is hard work and I don't think anyone would give their guys anything that hasn't been passed or ticked off."
Having the New Zealand Rugby Union involved with the franchises, he believed, was a major benefit.
"Because the NZRU owns all the franchises and the high performance sports science guys will want to be across everything like that."