Russian and American crewmen on the Mir space station have made another abortive attempt to locate the leaks in a section of the orbiting complex which was punctured in a collision a year ago.

Fluorescent gas was pumped into the damaged Spektr laboratory module, but none of the nine astronauts could see any sign of it escaping into the vacuum of space.

The experiment will be repeated on Monday when the Americans undock their shuttle craft and fly alongside Mir, giving improved visibility.