The South Korean defense ministry said on Monday that it has confirmed the detection of an explosive chemical substance RDX, commonly used in producing torpedoes, from the stack of sunken naval warship "Cheonan" as well as sand collected from the seabed of the explosion site.

"It is true that traces of RDX, an explosive used in the production of torpedoes, have been detected," the ministry said in a statement.

However, the ministry said that RDX, which stands for research department explosive, is not a substance used exclusively in the West, as was reported by various press agencies, adding that it is commonly used worldwide within the military and industrial sectors of all nations.

"RDX is an explosive that has been used since World War II by many countries, including the defunct Soviet Union and other socialist nations," it said.

Some media reports indicated the explosive chemical substance is used only in Western nations, raising speculation that the traces found in the sunken ship might have come from South Korean weapons used in drills near the area.

The defense ministry added "groundless guesswork can negatively affect the response and follow-up measures," urging the South Korean people and the media to be patient and wait until the investigation team makes an official announcement.

"The Ministry of National Defense is fully devoted to clearly identifying the cause behind the sinking of the 'Cheonan' as quickly as possible. The multi-national joint civilian-military investigation team, comprised of top Korean and foreign experts, is doing its best to gather evidence and conduct a scientific analysis," it said.

The multi-national joint civilian-military investigation team, consisting of about two dozen experts from the United States, United Kingdom, Australia and Sweden, have been working with South Korean experts to identify the exact cause behind the explosion of the naval warship "Cheonan."

The 1,200-ton Navy frigate "Cheonan," with 104 crew members onboard, went down on March 26 near the South Korean island of Baekryeongdo off the west coast due to an unexplained explosion that split it in two, killing 46 sailors.