Girlfriend witnesses partner's shooting death as bizarre new detail emerges

Two men are on the run following a fatal shooting inside an apartment in Sydney’s southwest.

Father-of-four George Nassiff, 46, was visiting the Warwick Farm property late on Sunday when his killers knocked on the door and shot him once in the back.

“It was just screams after the gunshot,” a neighbour said.

Father-of-four George Nassiff was shot inside a Warwick Farm apartment on Sunday. Source: 7 News

Mr Nassiff’s emotional girlfriend Taylah witnessed the whole thing.

“The best man, he’s got the biggest heart,” she said.

“I can’t believe it that they’ve done this.”

The couple had been visiting the apartment when Mr Nassiff was shot.

George’s girlfriend Taylah witnessed the shooting. Source: 7 News

Police are now investigating if it was a set-up.

The complex was placed in lockdown after the shooting, with neighbours questioned and searched.

Police say the men were last seen three blocks from the scene, banging on doors and offering residents $1,000 to hide inside.

No-one let them in but one suspect left behind a key piece of evidence.

Detectives have seized several items, including a black jumper. Source: 7 News

Detectives have seized several items, including a black jumper, but despite a 25-hour manhunt the pair are yet to be found.

The two men were captured on security camera inside the lift of the apartment complex just moments before the shooting.

Their faces are covered but the images will be crucial to the investigation, and police say it is just a matter of time before the men are found.