They say the evidence of the Mars 3 mission, the first successful soft landing on the Red Planet, is in images taken in 2007 by NASA's Mars Reconnaissance Orbiter.
NASA reported their claims Friday.
"While following news about Mars and NASA's Curiosity rover, Russian citizen enthusiasts found four features in a 5-year-old image from Mars Reconnaissance Orbiter that resemble four pieces of hardware from the Soviet Mars 3 mission: the parachute, heat shield, terminal retrorocket and lander," the space agency said.
The Soviet space mission made a soft landing on Mars Dec. 2, 1971, and sent data back to Earth for 14.5 seconds before the transmissions stopped abruptly, RIA Novosti reported.
Russian space follower Vitali Egorov saw an image taken by NASA's orbiter of the crater where Mars 3 was believed to have landed, and recruited members of an online community that follows NASA's Curiosity rover to look for objects in the image that matched the Mars 3 equipment.
Alfred McEwen, principal investigator of the University of Arizona's High Resolution Imaging Science Experiment on the orbiter, was asked to analyze a follow-up image of Mars 3's landing site, and said the objects identified by the Russians could be the real thing.
"The parachute, which is seen as an especially bright spot, was the most distinctive and unusual feature in the images," he told RIA Novosti.