Tun Dr Mahathir Mohamad said Malaysia truly lost a great leader the day the country's second prime minister Tun Abdul Razak Hussein died in 1976, describing it as a personal loss to him.

Dr Mahathir, who himself served as prime minister, said he was particularly saddened because he owed everything to Tun Razak.

He recalled his expulsion from UMNO and that people who were expelled before him never returned, their political career blighted.

"But he not only allowed me to return to the fold but subsequently appointed me a full minister. I was described as Tun's blue-eyed boy," Dr Mahathir said in a blog posting.

He credited Tun Razak for breaking away from the apron strings of the British Commonwealth past and visited Russia and China as the winds of change blew strongly.

Dr Mahathir said he could not but felt sad as he watched a television documentary recently on the life and times of Tun Razak who was prime minister from 1970 to 1976. He died on Jan 14, 1976 in London at the age of 53.

"Those were great days. Leaders then were dedicated, bent on developing the country and tackling the disparities in Malaysian society. It was Tun Razak who introduced the New Economic Policy," he said.

Dr Mahathir said that as a doctor, he noticed early Tun Razak's deteriorating health.

"Before he left for the United Kingdom at a function at Parliament House, he pulled me aside and told me he was suffering from leukaemia. He told me to speak to his doctor, Dr Macpherson.

"I did, and knew that the periods of remission would get shorter and shorter. He would not be able to continue for long. Still I was shocked to hear of his demise. Malaysia truly lost a great leader," he said.

Dr Mahathir said Tun Razak could have made a real difference to the future of this country which he fought so hard for.

"For me the loss is personal. Tun Hussein (Onn) who succeeded him was never close to me and I thought that that was the end of my career.

"But it wasn't. It wasn't because Tun Razak had spoken a good word for me to Tun Hussein," he said.