The Russian Federal Space Agency says it consulted with Korean authorities in replacing South Korea’s first astronaut.

Earlier on Monday, the Education, Science and Technology Ministry announced that Ko San will be replaced by backup trainee Yi Soyeon.

The agency’s Director Anatoly Perminov said Tuesday that Korean authorities decided to replace Ko with Yi after consultations with Russia’s cosmonaut training center.

Perminov said the replacement came after Ko violated regulations, adding that the process should go smoothly as there's enough time before Yi travels to space. He stressed that Yi had undergone the same training as Ko.

But the Russian official did not say what regulations Ko had broken.

Ko and Yi were chosen as the final two in December 2006 from a pool of 18-thousand candidates. The top-ranked Ko had been training with two Russian cosmonauts to go into space aboard the Russian Soyuz spacecraft on April eighth. Yi had been training as a backup.

Yi will conduct scientific experiments at the International Space Station during her ten-day mission.