Al-Arabiya reportedly broadcast a report showing Free Syrian Army rebels making claims that Russian Gen. Vladmir Kojaiv and his Syrian translator were killed in Syria.
The Russian Defense Minister issued a statement saying rebel claims were part of a smear campaign against Moscow.
"I want to confirm that I am well and alive, live in Moscow," the general was quoted by Russia's state-run news agency RIA Novosti as saying.
The Syrian government of President Bashar Assad counts Russia as a top military supplier. That relationship sparked criticism from U.S. Secretary of State Hillary Clinton, who accused Moscow of supplying helicopter gunships to the Syrian military.
Russia holds veto power at the U.N. Security Council. The government has objected to various efforts to censure the Syrian government, saying draft resolutions lacked balance.
An Iranian official this week said diplomatic support for the Syrian government formed part of an "axis of resistance" against Israel.