The plastic packets of the powder, found during a raid in the Brazilian capital, are stapled shut with a small paper logo featuring the five Olympic rings.
Written on the logo are the words: “Rio 2016. Keep away from children.”
The games-themed baggies were found among 93 packets seized by police officers during a raid in Lapa, central Rio.
It is just the latest controversy to blight what will be South America’s first Olympic games.
Fears about the spread of the Zika virus, high crime rates, and Russia’s state-sponsored doping have stolen headlines in the buildup to the event.
But the discovery of the drugs lends support to fears the city’s high rates of crime and violence could overshadow the international sporting competition.
Added to this are concerns about its sporting facilities – several Olympic teams have already complained about the unfinished state of their athletes’ accommodation at the village.