Russian inspectors have refused to blame North Korea for the sinking of a South Korean warship, an Indian online paper reported.

A team of four submarine and torpedo experts from the Russian Navy returned to Moscow on Monday after making an independent assessment of the March 26 sinking of the South Korean corvette, the Hindu reported Tuesday, quoting Russian military sources.

The paper said the experts had not found "convincing evidence of North Korea's involvement."

"After examining the available evidence and the ship wreckage, Russian experts came to the conclusion that a number of arguments produced by the international investigation in favor of the DPRK's [Democratic People's Republic of Korea] involvement in the corvette sinking were not weighty enough," a Russian Navy source was quoted as telling the Interfax-AVN news wire on Tuesday.

Russia's Armed Forces Chief of Staff Nikolai Makarov said only that the Russian Foreign Ministry would make an official statement on the issue after the experts prepared their report.

"It is too early to make a definitive conclusion on the causes of the tragedy," he was quoted as saying.

A leading Russian expert on Korea suggested that the ship had been probably hit by friendly fire. "I think it was a tragic accident during war games that cynical politicians are trying to exploit to maximum advantage," said Dr. Konstantin Asmolov of the Korea Center at the Institute of the Far East.