Singapore's first prime minister and the man widely credited with the city state's economic success, Lee Kuan Yew, is in hospital with severe pneumonia.

Lee, who turned 91 last September, was admitted on Feb 5, the office said.

"His condition has stabilised and he remains on mechanical ventilation in the ICU (intensive care unit). He is conscious and lightly sedated," the prime minister's office said in a statement on Saturday.

Although Lee has receded from the public and political scene, his health is watched closely as he is still seen as an influential figure for the government of Prime Minister Lee Hsien Loong, his oldest son.

Prime Minister Lee said on his Facebook page that he visited his father on Saturday morning, wished him a happy Lunar New

Year and a smooth recovery.

"This was the first year in a long while that we could not attend the Lee family reunion dinner," Lee Hsien Loong said.

Lee Hsien Loong, who himself was discharged from hospital on February 18, is recovering from a successful surgery to treat prostate cancer.

- Reuters