Bandits and drug traffickers are among the dangers lurking on a newly disovered stretch of the Amazon that may make it the world's longest river, an adventure recounted in the documentary "Peeled Faces on the Amazon."

U.S. kayaker West Hansen, leader of the Amazon Express, told EFE he was robbed, shot at and ended up on the wrong side of a gun twice during the journey.

Hansen is the first person to travel the 6,800 kilometers (4,225 miles) from the Amazon River's most remote source, discovered in 2012 by American James Contos, who determined that the Mantaro River is between 70 kilometers and 90 kilometers (43.4 miles and 55.9 miles) longer than the Apurimac River, until then believed to be the origin of the Amazon.

The expedition, organized by National Geographic, took 111 days to reach the Atlantic Ocean from the source of the Mantaro River, located 5,200 meters (17,049 feet) up in the Peruvian Andes and along the Ene, Tambo and Ucayali rivers to the confluence with the Marañon River, which becomes the Amazon before passing through Iquitos.

The course forced kayakers to navigate valleys carved by the Apurimac, Ene and Mantaro rivers through mountains and jungles in a constant state of emergency because remnants of the Shining Path guerrilla group operate in the region, which is home to almost half of Peru's illegal coca plantations.

"On the Ene River, we got to a village where the chief thought we were carrying drugs," Hansen said, adding that he later understood that the man's suspicions were warranted when the expedition found bundles of drugs in a backwater area.

As the explorers approached Poyene, a resident "became agitated and fired on the photographer's boat," Hansen said. "We were detained by armed men, but they apologized when the local chief arrived and invited us to spend the night there. The village looked beautiful in the moonlight bathing the jungle."

The journey down the Mantaro River posed many dangers for the explorers since its Class V+, or maximum difficulty rapids, with turbulent waters and unpredictable turns, require advanced techniques to overcome cascades, dips and whirlpools.

Hansen was assisted by expert Peruvian guide Juanito de Ugarte, who died in November 2014 and will be honored posthumously at the screening of the documentary at Inkafest.

"Without his leadership, this expedition would have failed," Hansen said. "More than once, he saved my life amid violent currents with such a calm demeanor that I almost didn't notice the danger until I looked back."

The expedition was robbed in the Brazilian Amazon by five bandits who stole the camera after searching the baggage for drugs.

"They were very nervous and we thought that they might accidentally shoot us," Hansen said.

"As the river became wider and wider, we had to deal with strong currents caused by tides and once on the ocean we faced 10-meter (33-foot) waves in the middle of the night, which was truly scary," Hansed said.