MANILA (Reuters) - The Philippines has suspended a third nickel mine in less than two weeks and again warned miners not to violate environmental laws, the Cabinet secretary overseeing mining told a radio station.

Regina Lopez, secretary of the Department of Environment and Natural Resources, told the Manila station DZMM on Saturday (July 16) a suspension order was slapped on Friday on Berong Nickel Corp's mine on Palawan because of a spill that affected corals.

Palawan, in the southwest Philippines, has become popular with tourists in recent years.

Lopez said while the spill was not intentional, company authorities "really need to get their act together".

She described Palawan as "the number one (tourist) island destination in the entire planet".

A top official of unlisted Berong's stakeholder DMCI Holdings Inc said on Sunday he was not aware of the suspension order and the spill incident. "Sorry, I am not aware. Will check tomorrow," Isidro Consunji, chairman and CEO of DMCI, said in a text message to Reuters.

DMCI owns Toledo Mining Corp, which has management control over the Berong project. Berong Nickel, which last year produced 868,000 tonnes of nickel ore, is a joint venture of Toledo Mining and another Philippines-listed firm, Atlas Consolidated and Mining Development Corp.

The Palawan nickel mine is the biggest of five slapped with suspension orders in the past two years, including two early this month.

The crackdown on miners by the government of President Rodrigo Duterte has sparked some concerns about ore supply to China, the world's biggest nickel consumer. At present, the Philippines is the top supplier of nickel ore to China.

A one-month audit of all Philippine mines starting July 8 is under way and Lopez, a staunch environmentalist, said she was unhappy with the initial reports.

"If they (miners) are not doing well and they are not following the law, we will withdraw the ECC (environmental clearance certificates)," she said on radio.