The scientists claim to have traced the river's source to a snow-capped mountain in southern Peru, adding a new twist in the swirling debate over the longest river label.

The Amazon is considered the world's largest river by volume, but scientists have believed it is slightly shorter than Africa's Nile.

The Brazilian scientists' 14-day expedition extended the Amazon's length by about 176 miles (284 kilometers), making it 65 miles (105 kilometers) longer than the Nile.

According to the team's results, which have not been published, the Amazon is 4,225 miles (6,800 kilometers) long. The Nile stretches 4,160 miles (6,695 kilometers).

"Today, we can consider the Amazon the longest river in the world," study author Guido Gelli, director of science at the Brazilian