New South Wales Police have described the shooting of the Ibrahim family bodyguard Semi Ngata in a western Sydney backyard as "brazen" and "targeted".

Key points: Semi Ngata is in a serious but stable condition at Westmead Hospital

Semi Ngata is in a serious but stable condition at Westmead Hospital A wedding between an Ibrahim and a Mehajer is to be held today

A wedding between an Ibrahim and a Mehajer is to be held today NSW Police seized two guns from a second crime scene in nearby Mays Hill

Mr Ngata, 59, was found outside the home of underworld figure John Ibrahim's mother on Price Street in Merrylands about 10:45pm yesterday, with a gunshot wound to his back.

He is in a serious but stable condition at Westmead Hospital.

A police source told the ABC a wedding between Mr Ibrahim's nephew Sam and Aisha Mehajer — sister of former Auburn deputy mayor Salim Mehajer — is expected to be held at the house later today.

NSW Police Chief Inspector Bradfield Peters said the shooting took place in the backyard of a house on Price Street.

Semi Ngata (L), and John Ibrahim smile for a photo. ( Instagram )

"If that's exactly what occurred then it is certainly brazen," he said.

"We believe that it's certainly not random and that it was targeted."

Mr Ngata — also known as "Tongan Sam" — has had surgery, and is refusing to cooperate with police.

Bleak start to big day

The names of Sam and Aisha along with today's date have been drawn on the pavement outside of the main Ibrahim family home, where there are rows of white chairs, shade cloth and a small marquee in the backyard.

The nuptials were flagged on the footpath on Price Street in Merrylands. ( ABC News: Siobhan Fogarty )

It is understood Sam is the son of Maha Ibrahim, who is John Ibrahim's sister.

The source said "police found material for a wedding" at the crime scene in Price Street at Merrylands last night.

However, Chief Inspector Peters would not speculate if the events were linked.

"We've only just found out that there may have been a wedding planned for today," he said.

"But whether there's any link to what occurred last night, I can't speculate."

As deliveries for the wedding began arriving at the property, tensions were high and at one point, journalists were pushed.

Aisha Mehajer (L) is the sister of Sydney property developer Salim Mehajer. ( Pictures: Instagram / AAP )

It is understood NSW Police seized two guns from nearby Mays Hill, where a second crime scene had been set up after a car was found burnt out.

"Not long after that shooting, that car was found burnt in Rees Street," Chief Inspector Peters said.

"If any members of the public have information about either of those two events we'd certainly like them to ring Crime Stoppers."

Forensic officers spent several hours in the garage and the back of the home on Patricia Street and removed up to 10 bags of evidence.