The incident happened shortly after they just touched down in the city, reported Ace Showbiz.
Leto, 43, was questioned by police officers when he and his travelmate were about to get into a car. The police officers said they responded to a possible battery.
After the law enforcement had finished talking with everyone involved, they determined no arrest was needed.
Apparently, they could solve the problem amicably as Leto's friend reportedly shook hand with the photographer following the talk.
It's unclear what led to the battery but the photographer was pictured having a bloody lip.
Leto is currently busy filming "Suicide Squad".