The ruling and opposition parties clashed Wednesday over whether the parliament should open a probe into a controversial project to refurbish the country's four major rivers.

Woo Yoon-keun, floor leader of the main opposition New Politics Alliance for Democracy, pressed for a parliamentary probe, saying a government investigative commission did not mention environmental damage and builders' collusion in the bidding process for construction contracts.

He also said that his party could not buy the assessment of the investigative commission that the project has achieved some accomplishments.

Meanwhile, the ruling Saenuri Party accused the opposition party of launching a political offensive over the results of the investigative commission.

Lee Koon-hyon, secretary general of the ruling party, also expressed deep regret over what he said was the opposition party's attempt to use the previous government's project as a political weapon, citing a 2012 appeals court ruling that said the project was legitimate.

Still, he called on the government to come up with measures to address water leaks at the concrete water receivers of the water pools in some dams to alleviate public concerns about the project.

The comments came a day after the government commission said six of the 16 dams built on the nation's four major rivers have minor structural problems.

But the commission said the 16 dams have no serious safety problems and the project also has successfully lessened the risk of flood in the areas adjacent to the rivers and enabled the use of pooled water for drought-hit areas.

The 22 trillion won ($19 billion) project of former President Lee Myung-bak has long been at the center of controversy over allegations of shoddy construction, irreversible environmental damage and collusion in the bidding process for construction contracts. (Yonhap)