Unconfirmed reports published Monday suggest that the head of Russia's secretive military intelligence service, who died last week, was injured in Syria and later died of his wounds in a Lebanese hospital.

The Al-Diyar newspaper, which is considered to be close to the Syrian regime, said that Igor Sergun was transferred to the American Hospital in Beirut for the removal of bullets from his chest but did not survive the surgery.

Russia denies the claim and says that Sergun died in Moscow.

President Vladimir Putin said in a statement on January 4 that Sergun was "a true officer, an experienced and competent commander, a person of great courage and a true patriot."

Sergun died on January 3, the defense ministry said at the time without disclosing the cause of his death. He headed Russia's Main Intelligence Directorate (GRU) since 2011, and landed on the US and EU sanctions lists over Russia's annexation of Crimea from Ukraine in March 2014.