The former All Blacks doctor John Mayhew says if former New Zealand Rugby Union employee Jack Ralston has evidence of All Blacks using steroids he needs to make it public.
The Press newspaper says Ralston, the former coach of triathlete Hamish Carter and former head of sales and marketing at the NZRU, makes the allegation in his yet-to-be-released biography, The Sports Insider.
Ralston says he knows of at least two All Blacks who took steroids in the 1990s to bulk up.
John Mayhew was the All Blacks doctor over that period and says he's certainly not aware of players using steroids.
He says there was extensive drug testing undertaken and if Ralston has evidence of steroid use he needs to make it public, as it casts a slur over all players from that era.