South Africa's ambassador to Japan has sent a letter of protest to the Sankei Shimbun over a column by prominent author Ayako Sono praising the racial segregation of apartheid as a model for Japanese immigration policy, according to the daily's publisher.

Sankei Shimbun Co. said that Ambassador Mohau Pheko took aim at the column published in the newspaper's Wednesday editions, in which Sono wrote that it is better for people of different races to live separately, just as they did under South Africa's former policy of racial segregation.

In the letter, received Saturday, Pheko was quoted as calling apartheid a crime against humanity that cannot be justified in the 21st century, adding discrimination on the basis of skin color is unacceptable in any country.