The incident happened on March 25.
It is believed the three were worshipping at the same church, but in different branches around Tembisa.
It is claimed the shooter, who was a senior pastor at 12th Apostolic Church, called the victims to his house to have a conversation.
It is also alleged the three had had differences in the past and the two pastors, who were shot, had started their own branches.
According to the Ivory Park SAPS communications officer, Warrant Officer Neldah Sekgobela, one of the victims who was shot and killed was the shooter’s son-in-law.
“The three had a conversation in the lounge. The pastor’s daughter, who is married to one of the victims, was in the main bedroom when she heard the gun shots.
“She went to check what was happening and saw her father holding a firearm. He told her to run away and hide. It is claimed her father then entered his bedroom and shot himself,” said W/O Sekgobela.
Two cases of murder and an inquest docket were opened at the Ivory Park SAPS.
The Ivory Park SAPS station commander, Brigadier Mthombeni, urged pastors to consider counselling whenever they have differences.
“Church leaders must consider professional help to sort out differences,” he said.
