A 59-year-old man was presented to an examining magistrate on Monday evening as part of a murder investigation, said France Bleu.
The individual is suspected of being involved in the death of his 87-year-old mother.
The latter was found dead on Saturday, in Astaillac (Corrèze).
The emergency services had been alerted for a drowning after a fall of the octogenarian in the Dordogne.
An investigation had been opened to clarify the circumstances of the accident and the body of the victim was autopsied in Limoges, indicates the local radio.
With his mother at the time of the incident
According to information from the daily La Montagne, the son was at his mother's side during his walk along the stream.
He would have said, at first, to have tried to get the octogenarian out of the water before alerting the emergency services.
The Limoges public prosecutor's office has asked for the man to be placed in pre-trial detention, adds local radio.