Gardaí are investigating following the discovery of a woman's body in the River Moy, near Foxford.
The body was found at 9.15am and has been taken to Castlebar Hospital for a post mortem, which will take place tomorrow.
The woman is believed to have been in her 40s.
Gardaí say foul play is not suspected.
Yesterday, the body of a 59-year-old man was taken from the river, at Ballina.
He had been involved in a search for a 19-year-old man, who was last seen on a bridge over the river, 11 days ago.
Navy divers are still searching for him.