The Democratic Alliance is appalled by the placing of a pig's head on a property earmarked for the construction of a mosque in Malvern, KwaZulu-Natal, the party said on Friday.
"The DA strongly condemns the defilement of the sanctity of any place of worship, in any manner," said spokesperson Sizwe Mchunu.
He said the head and several pictures of pigs were found on the property on Thursday.
"This smacks of religious intolerance and undermines our Constitution, which guarantees freedom of religion."
Pigs are regarded as "haraam" in Islam. This means the consumption of pork and the use of products from the animal are forbidden to followers.