The young man, identified by La Repubblica newspaper as Andrew Cate Carr, a student at John Cabot University, “may have climbed onto the wall while joking around, then tripped and fell,” according to the chief police officer at Trevi police station.
Police have interviewed some of the victim’s friends who were present at the scene of the accident.
"We saw a person walk and jump onto the parapet," witnesses told police, before reporting seeing him stumble and fall off the wall.
Police have not yet determined whether the young man had been drinking that night.
Carlo Rienzi, President of Codacons – an Italian association for both the defence of the environment and consumer rights – told La Repubblica that this is the third time that an incident of this kind has occurred on the Tiber embankment in the last five years.