Japan will launch a survey of its Pacific seabed, an official said Thursday, hoping to find rare earth deposits large enough to supply its high-tech industries and reduce its dependence on China.

Researchers from the Japan Agency for Marine-Earth Science and Technology will start the probe from January 21 on the seabed near Minamitorishima island, some 2,000 kilometres (1,250 miles) southeast of Tokyo, he said.

Finding large-scale proven reserves inside Japan's exclusive economic zone would be a boost to Japanese industry, which currently relies on imports from China.

These imports have in the past fallen victim to the delicate political relationship between the two countries, notably in 2010, when manufacturers complained supply was being squeezed during a spat over disputed islands.

The row, over a Tokyo-controlled archipelago known as the Senkakus that Beijing claims as the Diaoyus, has flared anew in recent months.

The survey will follow an earlier finding by Tokyo University professor Yasuhiro Kato, who took mud samples from an area.

He said these indicated deposits amounted to around 6.8 million tonnes of the valuable minerals, or 220 times the average annual amount used by industry in Japan.

Rare earths are used to make a wide range of high tech products, including powerful magnets, batteries, LED lights, electric cars, lasers, wind turbines and missiles.

China produces more than 90 percent of the world's supply of rare earths, but has clamped down on exports of them in a move Beijing says is aimed at protecting its environment and conserving supplies.