Marilou Danley, 62, was named as a person of interest in the shooting at a country music festival that killed 58 people and injured 515, the deadliest mass shooting in US history. She is an Australian citizen who lived on the Gold Coast for more than a decade.

After sending out a request for her whereabouts, the Las Vegas Metropolitan Police Department said in a statement late on Monday night that "detectives have made contact with her and do not believe she is involved with the shooting on the strip."???

However, in an update on Tuesday morning, Las Vegas Metropolitan Police Department Sheriff Joe Lombardo said the gunman's female companion was still a "person of interest" and she would be interviewed when she returned to the US. Ms Danley was reportedly in the Philippines at the time of the shooting.

Las Vegas police said it was believed the gunman, identified as 64-year-old retiree Stephen Paddock, had used some of Ms Danley's identification to book the hotel room.

Relatives told the Washington Post and local media that Ms Danley had been Paddock's girlfriend for some time and lived with him.

"She's a nice lady, I've met her three or four times," Paddock's brother, Eric, told local TV station WKMG from his home in Orlando, Florida. "She's got a Facebook page. She sends cookies to my mum."

It is not clear what Mr Paddock's motive was, but police in the famous casino city have described him as a "lone wolf" shooter.

Paddock, 64, was shot dead by police after he began firing from the Mandalay Bay Resort and Casino into the 30,000 people below attending the Route 91 Harvest country music festival.

Hundreds of music fans huddled for cover or ran for their lives as the gunfire continued.

Police are preparing to search Paddock's home and said there was "no indication so far at this early stage that this was a terror attack".

Ms Danley's LinkedIn profile said she was a "gambling and casino professional" who lived in Reno, Nevada.

Between 2010 and 2013 she worked as a "hostess" for the Atlantis Casino Resort Spa.

There is no listing for her employment since that date. Facebook photos show her participating in a gambling tournament in Las Vegas in 2014.

She is believed to have relatives, including a sister, still living in Australia.

Las Vegas Metropolitan Police Sheriff Joseph Lombardo said late on Monday night that police had located Ms Danley, who was earlier named as a person of interest in the shooting.

"We have located the vehicles that I had put out in the first briefing," he said.

"We are confident but not 100 per cent sure that we have located the female person of interest. I want the people to feel confident and calm that we have accomplished a lot in a short period of time."

Police in Mesquite, where Paddock's home was being searched, said he did not have a criminal record.

"We don't have a lot on Mr Paddock. He does live here in our city. We have not had any law enforcement contact with him in the past," Quinn Averett, a spokesman for the Mesquite Police Department, said.