China aims to launch a series of offshore nuclear power platforms to promote development in the South China Sea, state media said again on Friday, days after an international court ruled Beijing had no historic claims to most of the waters.

Sovereignty over the South China Sea is contested by China, the Philippines, Vietnam, Malaysia, Brunei and Taiwan, and any move to build nuclear reactors is bound to stoke further tension in the region.

The China Securities Journal said 20 offshore nuclear platforms could eventually be built in the region as the country seeks to "speed up the commercial development" of the South China Sea.

"China's first floating nuclear reactor will be assembled by the China Shipbuilding Industry Corporation's (CSIC) subsidiary, Bohai Heavy Industry, and the company will build 20 such reactors in the future," the newspaper said.

"The marine nuclear power platform will provide energy and freshwater to the Nansha Islands," it said, referring to the disputed Spratly Islands.

The newspaper was citing a social media post by the China National Nuclear Corporation (CNNC), which has since been deleted.

The Global Times, an influential tabloid published by the ruling Communist Party's official People's Daily, announced similar news in April and said the nuclear power platforms could "sail" to remote areas and provide a stable power supply.

"The news is old," an expert with the China Nuclear Energy Association said. "It is repeated in reaction to the latest South China Sea disputes," the expert, who declined to be identified, told Reuters.

"Little progress has been made on building such a small reactor."

Chinese Foreign Ministry spokesman Lu Kang, asked at a daily news briefing, said he did not know anything about the plans.

Floating reactors were first proposed in the United States in the 1970s but then abandoned. The first demonstration of the technology is due to be launched in Russia next year.