The 21-year-old, from Ramsgate, was held by police after the young woman's remains were found in Broadstairs, Kent, on Sunday.
Officers had been called to the Port of Ramsgate to reports of a person in the sea.
Kent Police said the man had been bailed until 24 June.
A man arrested on suspicion of murder after the body of a teenage girl was pulled from the sea has been released on bail.