He in his paper claimed that it is great possibility that "Cheonan" sank not because of a torpedo of the north but due to underwater explosion of a mine left by the south Korean navy in the 1970s.

He said he could draw this conclusion on the basis of an analysis of shock waves, sound waves in the air and underwater waves at the time of the incident.

He went on:

Reinvestigation is necessary because the results of the investigation into the Cheonan incident announced by the civilian and military joint investigation team failed to carefully deal with the nature of underwater explosion and dynamics.

The Solidarity for Social Progress of south Korea issued a commentary on August 28 in this regard.

His paper totally refuted the results of investigation announced by the "government" in which it claimed "Cheonan" was sunken by the torpedo attack of the north, the commentary said, and went on:

There were strong voices critical of the "government's" irresponsible investigation and acts to hide the truth about the incident and opposition to the results of investigation was repeatedly expressed in the meantime.

Nevertheless, the "government" completely suspended the south-north exchange by pursuing a policy of pressure upon the north including "May 24 step" while seeking political aims, not making any effort to clearly probe truth and thus steadily escalated the military tension on the Korean Peninsula.

Lee Myung Bak took the lead in kicking up a coloring ruckus against those people who put just questions.

There should be a comprehensive reinvestigation into the cause of the warship incident, the commentary concluded.