North Korean leader Kim Jong-il underwent heart surgery by a team of German doctors in April last year, a Japanese daily reported Saturday..

Citing a Korean government official who is alleged to have contacted one German doctor, the Asahi Shimbun said only a few Korean officials were informed of the surgery by one of the German doctors.

The daily said Kim recovered later, after undergoing coronary artery surgery in April 2007.

It is not known whether the recent news of Kim having a stroke was related to the surgery. The National Intelligence Service, Korea’s spy agency, confirmed the German doctors’ visit to Pyongyang at a National Assembly’s hearing session in June 2007. The agency, however, did not confirm whether the surgery took place.