The Prince of Wales has been described as a man of "zero prejudice" by the Asian friend he calls "Sooty".
Kolin Dhillon said the nickname used by Charles and other players at the Cirencester polo club where they are members was "a term of affection".
Charles has been branded "out of touch" for using the nickname, which refers to Mr Dhillon's skin colour, but the Prince's friend insisted he was not offended by it.
Mr Dhillon attempted to play down the criticism Charles received after it was revealed the heir to the throne had been calling him by the nickname for years.
He said in a short statement: "I have to say that you know you have arrived when you acquire a nickname. I enjoy being called Sooty by my friends who I am sure universally use the name as a term of affection with no offence meant or felt. The Prince of Wales is a man of zero prejudice and both his sons have always been most respectful."
Mr Dhillon is a former chairman of the Schools and Universities Polo Association but is originally from the Punjab and emigrated to Britain in 1955.
In the 1990s he hosted school polo matches at his home's private polo field that were attended by William and Harry when they were studying at Eton.
Mr Dhillon's real name is Kuldip Singh Dhillon but he is also known by the Anglicised name Kolin.
The race row comes a few days after Harry was widely condemned for calling a former Army colleague "Paki".
Prime Minister Gordon Brown branded the comment unacceptable and the Prince, an officer in the Household Cavalry Regiment, faces a dressing down from his commanding officer.
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