"The suspected man was born in 1986, he is a resident of another district of the Nizhny Novgorod region," - said in the message.
Investigators are working with the detainee.
On the evening of September 24, in a deserted place in the village of Neklyudovo, Nizhny Novgorod Region, the body of a nine-year-old girl who disappeared on the same day with signs of a violent death was found.
The UK opened a criminal investigation into the murder.