The Independent Police Investigative Directorate (IPID) is investigating whether a Durban metro police officer was responsible for Monday's shooting which claimed three lives, including his own.

IPID spokesperson Moses Dlamini on Tuesday said there was also speculation about whether the officer turned the gun on himself.

He said it was thought that the officer's gun was thrown out of the first-floor window of his apartment.

"This is [obviously] unusual for a person who shot themselves. We are currently investigating to determine if the policeman indeed shot anyone. Also, if his gun was used, was he the one who shot those people?"

He, however, said IPID was not ruling out anything.

WATCH: Metro cop among 3 killed in 'bloodbath' shooting near Durban High Court

"At this stage, we do not know if the policeman is responsible for shooting, because the firearm appears to have been thrown out the window."

The constable, 39, was found dead in his apartment along with two others. Five other people who were at the scene were also shot and injured while another person escaped unharmed.

Investigators were seen leaving Baker Street with a Glock 17 firearm, a standard issue for metro police officers.

Dlamini said that if investigations reveal the officer is responsible, IPID would take over the investigation.

"We are working closely with SAPS investigators to a point where we are able to determine who is responsible. If it is the police officer, we will take over the investigation."

Rescue Care spokesperson Garrith Jamieson, whose team was part of the first responders, described the scene as an "absolute bloodbath".