"The potentially dangerous melamine was found in a Russian-made product," the source at the local consumer rights regulator told RIA Novosti.
The tainted milk powder was found at one of the region's food warehouses. Checks are continuing in other wholesale stores.
Russia on Tuesday banned the import and sale of all Chinese food products containing milk derivatives following cases of melamine poisoning in China, citing a lack of official information from Beijing.
A day later, food products containing banned Chinese powdered milk were found in the Khabarovsk Region in Russia's Far East and withdrawn from sale. It is still unclear whether they contained melamine.
No cases of poisoning from melamine-contaminated products have so far been registered in Russia.
An estimated 53,000 Chinese children were sickened by milk-based food products, and four babies died of kidney failure.