Mr Kim, 66, reportedly suffered a stroke and underwent brain surgery in August. But Pyongyang has denied he is ill and has in recent weeks has released news reports, photos and footage portraying him as active and able – all of which have left doubt about his true condition.

Yesterday afternoon, North Korean state television showed an undated still photo of what it said was Mr Kim watching a football match between two army-affiliated teams.

It depicted him sitting with other people, watching something from what appeared to be a special viewing stand inside a building. Mr Kim was shown smiling, wearing his trademark sunglasses with a brown jacket and black trousers, but there were no scenes of any football match. He also had a full head of hair, despite reportedly having had brain surgery in August.

The TV footage included 13 other shots of Mr Kim in the same clothes, talking to people near a field, although no football players were seen. The rest of the photos showed stand-alone scenes of a football match near a small hill, with trees showing autumn foliage.

An unidentified North Korean TV anchorwoman said Mr Kim had attended the football match between the Mangyongbong and Jebi teams of the Korean's People's Army, together with top military officers and Workers' Party officials. She did not say when and where the game had been played, but that Mr Kim had expressed "great satisfaction over a high level of the game played by them".

Last week, Mr Kim failed to attend the funeral of one of the most senior members of the communist state, South Korea said, again raising questions over whether he is fit enough to appear in public.

Speculation about the health of the North Korean leader reached a peak after he missed a key national celebration marking the country's 60th birthday on 9 September.

He had not been seen in public since mid-August.

Last week, South Korea's spy chief, Kim Sung-ho, said that the North Korean leader appeared to have recovered enough to carry out his official duties, although he was "not physically perfect".

Japan's Fuji television has reported that Mr Kim's eldest son, Kim Jong Nam, flew recently to Paris to recruit a neurosurgeon to treat his father. Taro Aso, the Japanese prime minister, told parliamentarians last week that the French doctor boarded a flight to Beijing, perhaps en route to North Korea.

Kim Keun-sik, a North Korea expert at South Korea's Kyungnam University, said Pyongyang released the photos to show the outside world again that Kim Jong Il had no health problems in running the country, because "speculation on his health has been endlessly raised".

Last month, North Korea released photos showing Mr Kim inspecting a military unit and appearing healthy. However, it did not say when the pictures were taken, sparking speculation that they might have been old because the lush green foliage appeared not to match the Korean peninsula's current autumn season.

Mr Kim has not publicly named any successors, leading to concerns about an uncertain future in the impoverished, nuclear-armed country.