JAKARTA - INDONESIA'S ailing former President Suharto has pneumonia and is developing the life-threatening blood infection sepsis, leading to a further deterioration in his health, his doctors said on Tuesday.

Doctors have been battling to save the 86-year-old former strongman, who ruled the vast Southeast Asian nation for more than three decades, since he was put on a ventilator after suffering multiple organ failure on Friday.

'It is clearly heading towards sepsis. There has been a decline in (his) digestive functions,' Dr Djoko Rahardjo of his medical team told reporters at a news conference.

Medical team chief Dr Mardjo Soebiandono said on Sunday there was only a 50-50 chance that he could survive.

'We are still observing. We have to identify the infection and the bacteria then we can proceed with the treatment,' Dr Soebiandono told Tuesday's news conference.

'His consciousness has declined. Heart, lung and digestive functions are all declining,' Dr Soebiandono added, noting there was no prospect of taking the former president off a ventilator at the moment.

Another doctor, Dr Muhammad Munawar, said on Monday the main focus of treatment was to ensure Suharto was supplied with adequate oxygen, and to prevent fluid building up and infection.

Suharto was taken to Pertamina hospital on Jan 4 suffering from anaemia and low blood pressure due to heart, lung and kidney problems.

The up-and-down fight for life by the former leader, who doctors say has come close to death on a number of occasions before rallying, has gripped Indonesia and led to a fresh look at his mixed legacy.

Suharto's rule was marked by rapid economic growth and political stability, but at a price that included severe restrictions on human rights, as well as endemic corruption.

With Suharto in a critical condition, the question of whether to continue legal proceedings against him for graft is being vigorously debated in the country.

A number of long-serving Asian leaders have visited his bedside in the last few days to pay their respects.

Suharto's friend and contemporary, Minister Mentor Lee Kuan Yew called at the hospital in south Jakarta at the weekend.

Mr Lee, 84, was prime minister for decades at the same time as Suharto's rule in Indonesia. He said he felt Suharto was not getting the honour he deserved.

On Monday, the 82-year-old former prime minister of Malaysia, Dr Mahathir Mohamad, prayed and whispered into Suharto's ear during his visit.

Brunei's Sultan Hassanal Bolkiah has also visited Suharto, who was forced out of office by mass protests in 1998. -- REUTERS