"Both black boxes – a flight data recorder and a cockpit voice recorder – have already been unearthed. They are in a satisfactory condition," the source said.
The tactical bomber crashed seven kilometers (four miles) from Marinovka Airport outside the city of Volgograd. Its fragments were found scattered across an area of four hectares (10 acres).
The plane was carrying two crewmen. The Defense Ministry confirmed Thursday there were no survivors.
A special commission is now looking into the cause of the deadly crash. It consists of an expert panel from the Russian Air Force and the Armed Forces flight safety authority. RIA Novosti's source said a technical malfunction or human error could have caused the crash.
Following the incident, the Defense Ministry grounded all Su-24s, pending the results of the inquiry.