A pastor and his nephew who were murdered by a mob after the bodies of siblings Silindile Sifunda, 7, and her sister, Nontokozo, 6, were found in a ditch, were killed for nothing, Mpumalanga police said.

Pastor Bheki Malomane, 36, and his nephew Wonder Mbuyane, 24, were beaten and set alight by the community of Mganduzweni village near White River after they were accused of raping and killing the girls in April.

Provincial police have arrested 22-year-old Tshepiso Mokoena and said he had given them enough information that ruled out Malomane and Mbuyane in the attack on the girls.

Their houses were also torched, after a local traditional healer, who was consulted by the community, ruled that Malomane and Mbuyane were involved in the murders of the two little sisters.

The community also claimed that one of the girls was mutilated. Police have dismissed this allegation as a lie.

Simon Mdluli, and older relative of Malomane and Mbuyane, said his kinsmen each had two children.

"Our hearts are very sore because someone who claims to be a sangoma wrongfully pointed out our children and said they were responsible for this gruesome crime and they were killed," Mdluli said.

"Four children are now orphans, they do not have a place to stay. We are pleading with the police to also arrest the sangoma and there are many people who were involved here but only two have been charged [for their murders].

"It's painful that in this area once someone says you have committed crime, you are killed. Our children didn't get a chance to clear their names."

Mokoena was arrested on May 28 for the murder of 20-year-old Khensani Sambo who went missing on March 26.

She was found buried in a shallow grave behind Jerusalem High School in Mganduzweni. Col Mtsholi Bhembe said Mokoena confessed to have also been responsible for the disappearance of the two girls who he allegedly handed over to other people for muti purposes.

The pastor and his nephew were not involved, Bhembe said.

Tobias Simelane, 44 and Getrude Ndubane, 45, have been charged with the murder of the two men and were remanded in custody.

They have not been asked to plead on two charges of murder and two of arson when they appeared in the Masoyi magistrate's court on Wednesday.

"We are sure there's more people to be arrested over the murder of the children as the accused is still in custody, investigations are advancing very fast.

"We would also want to warn the public to work with us and not take the law into their own hands because that is crime on its own," Bhembe said.

He said police were also investigating the traditional healer and were confident that an arrest would be made soon.

At least six people accused of crimes have been murdered in these densely populated communities near the Kruger National Park.

In Masoyi, the villagers told Sowetan they often take the law into their own hands because police were hesitant to act.

Mozambican Surprise Mlimi, 43, was brutally assaulted and his house burnt after Isabella Gumbi, also from Mozambique, disappeared.

But Gumbi had not died but had taken a taxi to Gauteng.

Two men accused of robbing bakery delivery vans were burnt to death in Masoyi.