Valery Ostapets, the president of Russia's Union of Juice Producers, was attacked on Saturday while walking his dog in the town of Krekshino some 24 km (15 miles) west of Moscow.
"The attackers began beating the entrepreneur with baseball bats," the source said. "On hearing the screams, his wife ran outside and the assailants fled."
Ostapets died from head injuries in hospital.
A spokeswoman for the union of juice producers confirmed the report.
Police have launched an investigation into the murder.