Eighteen people arrested last week while trying to enter Nicaragua disguised as a news crew from Mexico's Televisa television were carrying $9.2 million in cash, police said.
The money was hidden in several of the six news vans - painted with the Televisa logo - the suspects were driving at the time of their arrest, police spokesman Fernando Borge told EFE.
Traces of cocaine were found in the group's luggage. Televisa said the detainees are not employees of the network.
Arraigned Saturday on charges of money laundering and racketeering, the 18 suspects are being held without bail.
The group tried to enter Nicaragua from Honduras en route to Costa Rica, Nicaraguan prosecutors said.
One of the 18 people arrested appears to be a municipal police officer from the Mexican city of Durango.
The phony journalists were intercepted shortly before the beginning of a high-profile trial in Managua of 24 people accused of smuggling Colombian drugs via Costa Rica to Guatemala, for ultimate delivery to traffickers in neighbouring Mexico.