The Japanese Government is secretly hatching plans for a huge underwater treasure hunt in the depths of the East China Sea in an urgent effort to secure supplies of the “vitamins of industry”.

The ambitious project, which could begin as early as next spring, will probe the seabed for deposits of ultra-rare metals used extensively by Japanese electronics manufacturers and other cutting-edge technology players.

In a briefing with The Times, senior officials at the Ministry of Economy, Trade and Industry (METI) described plans to tap “huge, black submarine boulders” for possible deposits of rare metals extruded from the Earth's core. If the state-sponsored quest is successful —and its multimillion-pound budget seems certain to win parliamentary approval — Japan may realise an old dream of resource independence from its sometimes troublesome neighbour China.

Unfortunately, the METI official admitted, the prospecting itself could becomea trigger for acrimonious disputes between Tokyo and Beijing.

Two spots of seabed are seen as rich with potential: one is near a remote Japanese island that featured in the Godzilla movies; the other is near a hypothetical exclusive economic zone border in the East China Sea that has historically proved to be politically explosive.

Chinese exploration for oil and gas in the area has already caused low-level confrontations in the high seas, and negotiations over how the resources beneath the zone may be shared have repeatedly collapsed without resolution.

The “vitamins of industry” scheme, which is based on an untested theory of volcanic science and geology, comes amid rising fears in Tokyo that the country's much-prized high-tech companies — the likes of Sharp and Sony — may be at risk. Soaring international market prices of metals such as gallium and indium are already hurting makers of liquid crystal display (LCD) televisions and semiconductors, but the new worry is that their supply could grow increasingly unstable.

As import arrangements stand, Japan buys virtually all of its rare metals from China and a handful of African countries: the emerging concern is that those lines of supply could suddenly be cut off or diverted at short notice.

The thinking behind the Japanese underwater treasure hunt is more than two decades old, and the revived enthusiasm highlights the new mood of insecurity. Japanese scientists first pointed out in 1985 the possibility that seafloor hydrothermal deposits may contain usable traces of rare metals. These deposits, which appear in the form either of large boulders or vast planes of black rock, are spewed out of underwater volcano vents along with giant spurts of superheated water.

Since there has been little analysis of the deposits, nobody is entirely sure how much gallium, germanium or indium is locked within them. Some scientific advisers to the Japanese Government have speculated that the rocks may contain larger troves of copper and zinc ores.

The treasure hunt is expected to be concentrated on two main areas already identified as bountiful with the mysterious black rocks. One is on the seabed around the Ogasawara Islands — a tiny inhabited archipelago in the Pacific to the far southeast of Japan that technically remains a part of Metropolitan Tokyo. The other, more controversially, is to the west of Okinawa in an area where China and Japan fiercely reject the notion that the other has any drilling rights.

“We simply have no idea how Beijing will respond to this exploration project,” the METI official said.

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