The Pan American Health Organization allegedly has collected more than $75 million since 2013 by allowing illegal human trafficking of Cuban doctors in Brazil, according to a new lawsuit.

The doctors were allegedly paid a fraction—10 percent or less—of the fees the Brazilian government paid to PAHO for their services, while PAHO paid at least 85 percent to the Cuban government, and retained a 5 percent brokerage fee for itself, the lawsuit filed in the U.S. District Court for the...