A senior member of South Africa's governing African National Congress (ANC) will be privately prosecuted on charges of animal cruelty after dozens of animals and birds allegedly died of hunger on her farm - and surviving pigs were forced to eat dead pigs, campaign groups have said.

More than 160 animals had to be put down after "absolute cruelty" was witnessed on the farm of Thandi Modise in 2014, a spokeswoman for the Society for the Prevention of Cruelty of Animals (SPCA) is quoted by South Africa's Eyewitness News site as saying.

Lobby group AfriForum's lawyer Monique Taut tweeted that the SPCA had found the carcasses of "pig, sheep, goat, goose and duck" on the farm, and "some of the surviving pigs had to feed on pig carcasses to survive".

Ms Modise - who is the chairwoman of the South African parliament's upper chamber - has not yet commented on the move to prosecute her.

When the allegations first surfaced, Ms Modise was quoted as saying that the farmer manager had been away because of a family emergency when the alleged neglect of the animals took place.

I am not a farmer. I am trying to farm. I am learning. But if you are a woman and you are learning you are not allowed to make mistakes, the IOL news site quoted her as saying.

About 85 pigs had been found starving on the farm, and they had been feeding off the carcasses of 58 dead pigs, local media reports said at the time.

South African law allows a private prosecution when the state's National Prosecuting Authority (NPA) refuses to charge someone.

In April, the NPA reversed its decision not to charge ex-President Jacob Zuma's son with culpable homicide after AfriForum said it would bring a private prosecution against him.

Duduzane Zuma was involved in a car crash which left two people dead in 2014.