Former prime minister Dr Mahathir Mohamad today published two letters, said to be from his then deputy Musa Hitam, to rebut Musa's claim that he resigned from cabinet after Mahathir accused Musa of trying to oust him.

Musa said this in his recently published memoir 'Frankly Speaking'.

Instead, Mahathir said on his blog, Musa resigned because he did not like Mahathir offering Gua Musang MP Tengku Razaleigh Hamzah the trade and industry minister post in 1984.

"To see how truthful Musa's frank story about himself, please read his two letters. The copy of the original is not legible, so I have printed the contents. You can compare," Mahathir said.

The original letters were not published in full, but Mahathir appended a transcript of what was written.

He also said he cannot uphold Musa's desire for secrecy, by publishing the letters, since Musa's memoir implies he has nothing to hide.

The first letter, said to be written on July 5, 1984, was marked 'Top Secret' while the second letter, dated July 31, 1984 noted that the contents are secret.

Tengku Razaleigh was trade and industry minister from 1984 to 1987, while Musa Hitam was deputy prime minister from July 18, 1981 to March 16, 1986.

In 1987, Tengku Razaleigh challenged Mahathir for the Umno presidency leaving a rift that would lead to Umno to be declared illegal, after Mahathir won the polls in a razor-thin margin.

Mahathir said, snidely, that after reading Musa's memoir, he fully agrees that he was a dictator.

"Of course I was a dictator for 22 years, requiring everyone to be absolutely loyal to me.

"The (supreme council) of Umno and the cabinet were quite dumb as I was the only one to speak. They merely nod their heads and shout yes," Mahathir said in his trademark sarcasm.

"Incidentally, I would like to point out that all dictators, Hitler, Mussolini and Stalin, resigned voluntarily like I did. The mystery is how I managed to be elected five times," he quipped.