The American Central Intelligence Agency has failed in an attempt to recover nuclear missiles and code books from a Russian submarine which sank in three miles (5 kilometres) of water in the Pacific in 1968.

The C.I.A. has spent about 350 million dollars (152 million pounds sterling) on the venture but has managed to raise only about a third of the Russian "H" class submarine.

They recovered the front section of the submarine last July from the floor of the Pacific, south west of Midway Island.

The section contained the bodies of about seventy Russian seamen who had died when the submarine sank after an explosion.

They were given a burial at sea by the Americans.

The C.I.A. made the recovery effort with the aid of a ship, the Glomar Explorer, and a specially designed barge.

The barge was lowered to the ocean bed and a tractor-like device in it hooked onto the submarine and dragged it into the barge.

The submarine broke up as it was being lifted to the surface, however, and the sections containing the missiles and the code books fell back to the ocean floor.

Although hundreds of people worked on the project, it remained a close secret of the Government until news of it leaked out this week.