The boy was taken into temporary protective custody when he revealed that his parents slap him. This reason has been viewed with disbelief in Russia, where slapping children is still largely considered part of normal discipline.
Russia's main news channel broadcast footage of the boy coming home after escaping from the orphanage where he is being temporarily housed.
"I don't want to go back to the orphanage, help me! I want to be with dad and mum," he said on the video.
For Finnish child protection officials, taking temporary custody of a child who says he or she is being smacked by their parents is normal protocol. But the Russian media has posited that there may be hidden motives, and that the boy was taken simply because he has Russian roots.
A Russian ombudsman for children is in Finland to look into the matter.
Finnish social service personnel say they cannot violate confidentiality practices to comment publicly on the case. In Russia, this is being interpreted as a deliberate snub of Russian concerns.