MANILA - Acting Chief Justice Antonio Carpio on Friday corrected President Rodrigo Duterte's claim that China was in possession of the South China Sea.

• Duterte: South China Sea ‘already in China's possession’

While China is in physical possession of the entire Paracels, 7 geologic features in the Spratlys, and Scarborough Shoal, these constitute "less than 8 percent of the total area of the South China Sea," said Carpio, one of the lawyers who represented Manila in the arbitration case against Beijing for maritime rights in the regional waters.

"Factually, China is not in possession of the South China Sea,” Carpio said in a prepared speech that he delivered before doctors at the PICC in Pasay.

"About 25 percent of the South China Sea are high seas. Under UNCLOS, no state can possess or own the high seas, which belong to all mankind. Under UNCLOS, there is freedom of navigation and overflight in the high seas for all nations," he said.

UNCLOS or the United Nations Convention on the Law of the Sea is an international treaty which sets the rights and responsibilities of nations with respect to their use of the world’s oceans. It also sets limits on the various zones surrounding a country’s coastline.

On the sidelines of the ASEAN summit in Singapore on Thursday, Duterte had said it was not wise to hold military drills in the South China Sea because China was already in possession of the whole area.

“No because --- it’s not military drills because I said China is already in possession. It’s now in their hands. So why do you have to create frictions --- strong --- military activity that will prompt a response from China?” he said.

But Carpio asserted that the Philippines, under the UNCLOS, has exclusive sovereign rights to explore and exploit the natural resources in its exclusive economic zone, an area 200 nautical miles from the baseline.

“Like all other coastal states in the world, the Philippines under UNCLOS has exclusive sovereign rights to explore and exploit the natural resources in its EEZ in the West Philippine Sea, which is part of the South China Sea. If China can possess the South China Sea, then the Philippines cannot exercise its exclusive sovereign rights in the West Philippine Sea,” he said.

He added that all nations enjoy “freedom of navigation and overflight” in the EEZs, which means that marine vessels and commercial flights can pass through these areas without seeking permission.

Carpio is one of five candidates in the running to replace Teresita Leonardo-De Castro as chief justice of the Supreme Court.

His bid for the top magistrate post has not however silenced him and his West Philippine Sea advocacy.