A bus that crashed in Ecuador earlier this week killing 24 people was carrying 80 kilograms of cocaine.
The drug was hidden under false floors, Ecuador's attorney general's office said.
Another 20 people were seriously injured when the bus, which was travelling from Colombia, crashed into another vehicle around 40 kilometres east of Quito on Tuesday and tipped over.
Colombian police said the passengers, who were mostly Colombians as well as some Venezuelans and Ecuadorians, had been used as a distraction to mislead authorities.
Relatives of the victims told Colombia's El Tiempo newspaper that they had been invited on the trip for free and that it was to go as far as Peru.
The paper also reported that the bus, which belonged to Colombian transport company Cotrans, did not have the proper permits to travel outside the country.