Residents of the New South Wales town of Moama say they are devastated following the recovery of the body of a five-year-old boy in the Murray River allegedly drowned by his mother.

Police divers found the body about 11.35am (local time) this morning.

Although still to be formally identified, police believe it to be that of the five-year-old son of a woman, 27, who allegedly tried to drown both her sons on Thursday.

The boy's nine-year-old brother is in a stable condition at the Royal Children's Hospital in Melbourne.

The woman has been charged with attempted murder and is in custody in nearby Deniliquin.

Further charges are expected to be laid.

"He was so little. Five years old, he's barely lived," said one local woman of the discovery of the child's body in waters near Perricootta Road, northwest of Moama, this afternoon.

"It's devastating," she added after she and her young daughter placed a bouquet of flowers on a chain link fence near the scene.

"Yesterday no houseboats or speed boats were allowed here as police were searching," she said.

Normal activity has now returned to the river and its banks, with boats and wake-boarders sailing past the spot where the boy's body was pulled from the water just hours earlier.