According to spokesperson Ndileka Cola, IPID received a report alleging that an officer had been involved in the incident which occurred on Saturday morning.
It was investigating a case of deaths as a result of police action, Cola said.
"The IPID's investigators responded swiftly to the crime scene to conduct an investigation.
"The South African Police Services (SAPS) arrested the police officer who is alleged to have caused the death of three persons," Cola said.
She added, "IPID is gathering more valuable information relating to this incident through its investigation process".
News24 previously reported that IPID had also been investigating the circumstances around 30-year-old Leroy Oliphant's death. Oliphant died in police custody in Cape Town on Tuesday.
Oliphant, from Elsies River, was allegedly assaulted by a member of the police's Anti-Gang Unit.
His family claimed he was treated like an animal, saying "they beat him up until he died".
Cola said post-mortem results would confirm Oliphant's cause of death, while IPID continued with its investigation.
For more news your way, download The Citizen's app for iOS and Android.