The Korea Aerospace Research Institute claims that the failed second launch of Korea's first space rocket "Naro" may have been caused by faulty Russian parts.

The institute said that a defective bolt, which separates the first and second-stage rockets, is now being suggested as one cause of the failed launch in June of this year.

It said that a joint Korean-Russian probe committee will look into possible flaws with the bolt.

However, the institute warned against jumping to conclusions about the cause of the launch failure and added that a test of the separation bolt should be conducted by Russia.