MUCH-loved King Father Norodom Sihanouk has announced that his health is deteriorating and suggested that his final days are not far away.

In a letter dated December 1, but posted on his website Saturday, the former monarch said his "eminent Chinese doctors" were giving him frequent check-ups and had recommended he be hospitalised.

Sihanouk has been living in his palace residence in Beijing, where he says he has access to better health services. Last month he announced he would give up his life-long passion for filmmaking due to old age and poor heath.

"I have been helped through two very serious cases of cancer and lived to an advanced age, 87 years," he wrote.  

His Chinese doctor, he said, "does not dare talk about my death, but it is not so far away. I told him it will happen (soon), and that I prefer to die in my residence than at the hospital".  

While officials could not confirm the condition of the former king, Son Soubert - an appointee of the retired monarch at the Constitutional Council and son of former prime minister Son Sann - said he "heard His Majesty had been visiting the hospital".

He said that Sihanouk's singular role as a leader in the Kingdom was irreplaceable.

"As a figure of stability, he is still very important," he said. "The Cambodian people will be very sad and worried. I don't think any other leader in Cambodia has the same respect and love of the people.

"The King has been at the same time a father and a leader. Morally, politically, I don't think anyone has reached that stature."