In the letter, which has been published online by news websites, Zuma takes a swipe at former finance minister, Pravin Gordhan, whom he brands as a sellout along with former tourism minister, Derek Hanekom.
Gordhan and Hanekom are senior members of the ruling African National Congress (ANC)
On Pravin, Zuma wrote: "This privileged boy from Sastri College shows us that he would defend whites and their appointed crumb eaters‚ the white monopoly capital indunas‚ the black parasitical political stooges at all costs".
However, on Friday the SAHRC said it found the contents of this letter, in particular statements that promote hatred on the basis of race "offensive and disturbing and a clear violation of the right to freedom of expression as articulated in section 16 of the Constitution".
The commission will be seeking appropriate redress as empowered by the Constitution as well as the SAHRC Act, said the statement issued by Gushwell Brooks the communications coordinator for the rights body.
"The Commission is concerned by such statements being made within the broader context of hate speech, particularly on the basis of race, by individuals with a public platform."
African News Agency