This was reported on the official website of the regional department of the Investigative Committee for the Sakhalin Region.
At the end of August, the child was resting with his mother at sea and disappeared without a trace, the woman was previously found drowned.
"During the investigation and search activities, the body of the missing boy was found on the seashore eight kilometers south of the village of Shebunino, Nevelsky District," the ministry said in a statement.
The cause of the death of the minor has not yet been found out, the body was sent for a forensic examination.
In August, Sakhalin opened a case on the disappearance of two women who went into the forest near Mount Vaida and did not return.