MANILA, Philippines--Justice Secretary Raul Gonzalez has said there was nothing in the Constitution that would prevent the Philippines from conducting seismic studies with other countries.

He said he had read the Joint Marine Seismic Undertaking (JMSU) agreement among China, the Philippines and Vietnam and found nothing wrong with it.

The President could not be impeached based on an aboveboard agreement, he said in a phone interview.

Gonzalez said the Constitution would only come into the picture "if we will go into exploration with China and Vietnam."

He said the company that would carry out any such exploration should be 60 percent Filipino-owned, or the Philippines could enter into service contracts.

"The seismic survey is only data gathering. Can you find gas and oil if you do not survey?" he said.

At present, according to Gonzalez, about three trillion cubic feet of oil have been discovered in the area, and it is possible that more would be found. He also said the country needed oil, which was why the survey was important.

Gonzalez said an impending Senate investigation into the JMSU should not impede the implementation of the agreement.

"I don't think we should be affected by a Senate investigation on something we do legitimately," he said.

Gonzalez called those making a fuss about the JMSU "hecklers" whose comments, he said, usually saw print in the Philippine Daily Inquirer, parent company of INQUIRER.net.