Some people from the local community, who went to fetch water from the river in the morning, discovered the bodies yesterday floating slowly, with some wedged on the banks of the river, local media reported.
Locals said, they counted up to 50 bodies before going to inform authorities.
The communities surrounding the river said nobody was missing within and suspected that the dead bodies may have floated down a long distance from neighbouring Enugu state.
"Since our arrival, we have counted about 15 dead bodies floating on this river and we may not have seen the last. We were duly informed by the security agencies and we believe they will carry out investigations to tell us actually what transpired", the state commissioner for local government, Azuka Enemuo said.
Police spokesman for Anambra State, Emeka Chukwuemeka confirmed the incident and said that police would carry out a thorough investigation.
Dead bodies often float on Nigerian rivers after boat mishaps.
