The claim follows an expedition to Peru that is said to have established a new starting point further south and it puts the Amazon at 6.800 km (4,225 miles) compared to the Nile's 6,695 km (4,160 miles).
However the precise length of a river is not easy to calculate and depends on correctly identifying the source and the mouth. The new claim in Brazil follows an expedition by scientists, which is said to have discovered a new source for the Amazon in the south of Peru and not the north of the country as had been thought for many years.
While the exact location has yet to be confirmed from two choices, scientists say either would make the river the longest in the world.
Guido Gelli, director of science at the Brazilian Institute of Geography and Statistics, told the Brazilian TV network Globo that it could be considered as a fact that the Amazon was the longest river in the world.
The Amazon is now said to begin in an ice-covered mountain in southern Peru called Mismi. Researchers traveled for 14 days, sometimes in freezing temperatures, to establish the location at an altitude of 5,000 meters (16,400 feet).
The research was coordinated by the National Geographical Institute of Peru, with the help of their colleagues in Brazil.
Mercopress