Director of the Griffon Poison Information Centre Gerhard Verdoon said there had been a dramatic increase in the number of vultures killed for muti.
He said that previously "a traditional healer had to kill the animal himself for it to have the necessary powers but, now that it has become commercialised, all the principles have fallen by the wayside".
There was a belief that sleeping with the head of a vulture could give people the power to see into the future and allow them to predict winning lotto numbers or sports results.
Last week two men were sentenced to two years' imprisonment each for poaching two white-backed vultures and a tawny eagle in KwaZulu-Natal at the beginning of the year.
In June, 48 Cape griffon vultures and an African white-backed vulture were found poisoned near Swartberg in the same province.
Verdoon said: "While the global population of white rhino is estimated to be more than 20 000 individuals, Cape griffon vultures number far less than 10 000 individuals."
A study by the Endangered Wildlife Trust found that Cape griffon populations in the Eastern Cape, KwaZulu-Natal, and Lesotho could be eradicated in 44 to 53 years.