A problem with Russian computers on board the International Space Station has been caused by a solar panel installed by American astronauts.

A Russian space construction firm announced Thursday that the countries specialists believe that the new solar panel installed by the Atlantis astronauts during their spacewalk could be the origin of the breakdown," AFP reported.

Irina Gomenyuk., a Spokeswoman for Energia, which designed much of the station said this "new powerful source of energy caused a malfunction of sensitive system elements" of the station, in particular the electrical supply system.

Earlier NASA had said that there had been a breakdown in communication with Russian computers that control the ISS critical oxygen and water supplies. Communication was later restored.

Two US astronauts spent more than seven hours outside the ISS Wednesday working on its solar power panels as part of a huge expansion of the station's electricity generation capacity.