At the deepest point on the planet, Vescovo found what looked like plastic.
American explorer Victor Vescovo, who has already scaled Mount Everest, the tallest mountain on Earth, made history by reaching the deepest place on Earth, the Challenger Deep in the Mariana Trench in the Pacific Ocean.
"Our team had to pioneer new camera systems that could be mounted on the submersible, operate at up to 10,000m below sea level and work with robotic landers with camera systems that would allow us to film Victor's submersible on the bottom of the ocean".
"It is nearly indescribable how excited all of us are about achieving what we just did", Mr Vescovo told BBC News.
Vescovo, the Dallas-based co-founder of private equity fund Insight Equity Holdings, found the man made material on the ocean floor and is trying to confirm that it is plastic, a spokeswoman for Vescovo's Five Deeps Expedition said.
Mr Vescovo's latest dive is part of the "Five Deeps expedition", where he is attempting to explore the deepest parts of all five oceans. "This submarine and its mother ship, along with its extraordinarily talented expedition team, took marine technology to an unprecedented new level by diving - rapidly and repeatedly - into the deepest, harshest area of the ocean".
It was the third time humans have dived to the deepest point in the ocean, known as Challenger Deep.
The scientists plan on testing the creatures they collected to see if they contain microplastics.
The team spent hours at the bottom of the ocean at these locations, collecting samples, including the deepest piece of mantle rock ever collected.
"So far, we've made up something like 150,000 square kilometers of deep sea floor now - and we're only halfway through it".
During their descent, the expedition crew saw a number of sea creatures - a spoon worm at 7000 metres and a pink snailfish at 8000m - and believe they discovered four new species of crustaceans called amphipods, similar to prawns.
Canadian filmmaker James Cameron was the last to visit in 2012 in his submarine, reaching a depth of 10,908 meters.
The deepest deep-sea dive ever may have just found them, the BBC reports.
When the Five Deeps expedition is complete, the researchers plan to pass their findings onto science institutions, which will continued to use their information for studies. They also found pollution.
A key mission objective was to capture video evidence of what was at the bottom of the Challenger Deep, which was first explored in 1960 by oceanographers Don Walsh and Jacques Piccard in submersible called Bathyscaphe Trieste. The pressure at the bottom of the ocean is equal to about 50 jumbo jets piled on top of a person, according to BBC News.