Locals suspect drug link to NSW murders

A drug dispute could have led to a double murder beside a southern NSW road, but police say that is only one of many possible motives for the killings.

Jamie Edwards and Joelene Joyce were shot dead in a car beside an isolated, unsealed road outside the Murray River town of Moama.

Mr Edwards, of Moama, and mother of four Ms Joyce from nearby Mathoura, both 36, were killed between Tuesday afternoon and Wednesday morning, when a local man came across the horrific scene.

Murray Shire mayor Tom Weyrich says he suspects a drug connection.

"The speculation is that this is drug-related," he said on Thursday.

Superintendent Paul Condon said the pair were known to police but drugs or a falling out with the Echuca chapter of the Bandidos bikie gang were only two theories.

"We are looking at all avenues of inquiry and that includes outlaw motorcycle gangs, drugs, whether it's a civil dispute, a personal dispute, a family dispute," he told AAP.

Someone in Moama or Echuca held the key to the investigation, Supt Condon said.

A strike force, Operation Keneddia, assembled on Wednesday to investigate the killings.

It includes four Sydney homicide detectives, four detectives from the NSW Police southern region, ballistics experts, forensics officers and local detectives.

State Emergency Service and Rural Fire Service crews are helping search the scene in a sparse farming area about 8km north of Moama.

Meanwhile, the pair's relatives have left tributes for them on social media.

One of Ms Joyce's children posted a picture of her on Facebook with the caption: "RIP mum love you for ever and always."

Another relative posted: "R.I.P Aunty Jolene, I will always remeber your beautiful face ... You were such a strong women."

A cousin of Mr Edwards wrote on Facebook: "U was like my big brother, U was a good man n deadly father.

"U will b missed by so many brus, Rest in the dream time. Love n miss u xo."