Daniele Fulli’s bruised body was found by passersby on Tuesday afternoon, by the river in the southern Magliana neighbourhood, Corriere della Sera reported.
He was found with injuries to his groin and at the back of his neck, which one doctor said could be gunshot wounds.
Fulli was reported missing on January 5th and was said to have been suffering from depression, Corriere said.
Fabrizio Marrazzo, spokesperson for the Rome Gay Center where Fulli volunteered, said clarity was urgently needed to determine how Fulli died.
“If it was murder, a homophobic motive must be considered,” Marrazzo was quoted in Corriere as saying.
Fulli was close to a gay man known publicly as Simone D, whose suicide in October prompted a candle-lit vigil for gay rights by Rome’s Colosseum.
The news of Fulli’s death comes just days after a gay man in Rome committed suicide by throwing himself out of a seventh-floor window.
The unnamed 21-year-old died on Sunday evening in the south-east Torpignattara neighbourhood, La Repubblica reported.