Amid concerns over rugby league players mixing sleeping pills and energy drinks, it's been revealed top All Blacks were doing the same thing during the last Rugby World Cup.
Radio New Zealand has learnt the night out which got All Blacks Israel Dagg and Cory Jane in trouble ahead of the side's World Cup quarter-final in 2011 was fuelled by sleeping pills and energy drinks.
Reports at the time suggested the pair went on a drinking binge at a Takapuna bar less than 72 hours before the quarter-final against Argentina.
Radio New Zealand understands there was pressure from within the team for the pair to be dropped, however they weren't the only players involved in the practice.
Players apparently stockpiled sleeping pills from overseas trips and would compete to see who could stay awake the longest.
Radio New Zealand has been told that recent All Blacks have experimented with the sleeping pill cocktails and the practice is also prevalent at Super Rugby level.
Earlier this month the NZRU's general manager of professional rugby Neil Sorensen announced they were establishing an integrity unit who's brief would include uncovering the level of abuse.
Sleeping pills are not prohibited under World Anti-Doping Agency rules and the practice of mixing them with alcohol or energy drinks isn't illegal.