The Independent Police Investigative Directorate (IPID) is probing after a police officer reportedly shot and murdered a well known Nelspruit businessman who had become involved in an argument with a group of bikers.

Colonel Benjamin Bhembe said on Monday that Merwyn Masher, a 38-year-old father of three, had apparently stopped at the scene of an auto crash on Madiba Drive in Nelspruit in the early hours of Sunday morning, where an unknown person from Pretoria had been murdered in a hit-and-run auto crash.

The whole ordeal broke out when a motorcyclist, who was attending the annual Sunriders MCC Bike Rally in Nelspruit, slammed into a car.

A second car then crashed into the motorcycle. As the second car's passenger was trying to get out of the vehicle, she was hit by another car, which sped off. The woman was murdered immediately.

A while later, Masher stopped at the scene, along with other bikers who had also attended the rally. Masher repotedly then got in an argument with them.

During the altercation, Masher reportedly pulled out a gas pistol, according to Bhembe.

He reportedly held the gas pistol against one of the biker's heads, threatening to murder him.

Police apparently tried to negotiate for more than 30 minutes to get Masher to put the gun down and hand himself over.

Bhembe said Masher did put the gun away briefly, before pulling it out again and waving it around.

It was at this point that he was shot dead by an officer, Bhembe said.

Masher was announced dead on the scene by paramedics.         

His wife, Milly, was in the car when the shooting happened.

He also leaves behind three sons.