The security guard who led police to Las Vegas shooter Stephen Paddock has vanished, his union president said.

Jesus Campos had been due to break his media silence following the devastating attack on a music festival that left 58 dead.

But the night before his interviews were due to take place he disappeared, according to David Hickey of the Security, Police, and Fire Professionals of America (SPFPA).

Mr Hickey said he later received a message saying Mr Campos had been taken to urgent care facility UMC Quick Care, according to Fox News.

"For the past four days he's been preparing... we had a meeting with MGM officials, and after that meeting was over, we talked about the interviews, we went to a private area, and when we came out, Mr Campos was gone,” Mr Hickey said.

"Right now I'm just concerned where my member is, and what his condition is. It's highly unusual. I'm hoping everything is OK with him and I'm sure MGM or the union will let (media) know when we hear something."

A spokesperson for UMC Quick Care say they had "heard nothing" about Mr Campos attending one of their centres.

Las Vegas shooting – in pictures Show all 15 1 /15 Las Vegas shooting – in pictures Las Vegas shooting – in pictures People scramble for shelter at the Route 91 Harvest country music festival after gun fire was heard Getty Las Vegas shooting – in pictures People carry a person at the Route 91 Harvest country music festival after shots were fired David Becker/Getty Las Vegas shooting – in pictures People run from the Route 91 Harvest country music festival after gun fire was heard David Becker/Getty Las Vegas shooting – in pictures A handout photo released via Twitter by Eiki Hrafnsson (@EirikurH) showing concertgoers running away from the scene (C) after shots range out at the Route 91 Harvest festival on Las Vegas Boulevard EPA/Eiki Hrafnsson Las Vegas shooting – in pictures People lie on the ground at the Route 91 Harvest country music festival after hearing gun fire Getty Las Vegas shooting – in pictures A man in a wheelchair is taken away from the Route 91 Harvest country music festival after hearing gun fire David Becker/Getty Las Vegas shooting – in pictures People stand on the street outside the Mandalay Bay hotel near the scene of the Route 91 Harvest festival on Las Vegas Boulevard EPA/Paul Buck Las Vegas shooting – in pictures FBI agents confer in front of the Tropicana hotel-casino after a mass shooting during a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Las Vegas police run by a banner on the fence at the Route 91 Harvest country music festival grounds after shots were fired David Becker/Getty Las Vegas shooting – in pictures An injured person is tended to in the intersection of Tropicana Ave. and Las Vegas Boulevard after a mass shooting at a country music festival Ethan Miller/Getty Las Vegas shooting – in pictures Metro Police officers pass by the front of the Tropicana hotel-casino after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures A woman sits on a curb at the scene of a shooting outside of a music festival along the Las Vegas Strip AP/John Locher Las Vegas shooting – in pictures A cowboy hat lays in the street after shots were fired near a country music festival in Las Vegas Getty Las Vegas shooting – in pictures Las Vegas Metro Police and medical workers stage in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Sheriff Joe Lombardo (2-R) speaking during a press briefing in the aftermath of the active shooter incident on Las Vegas Boulevard EPA

Mr Campos was shot as he approached the 32nd floor suite of the Mandalay Bay hotel, from where 64-year-old gunman Paddock was firing customised automatic weapons into crowds at a festival below.

After raising the alarm with police, Mr Campos reportedly remained nearby, helping to evacuate rooms on the same floor before being ordered to leave himself.

He was hit in the right leg by a bullet and was due to be operated on. His injuries were not believed to be serious.

Mr Campos was hailed a hero for raising the alarm, and received a union award in the wake of the attack.

But he has also found himself at the centre of conspiracy theories surrounding the shooting.

Internet forums went into overdrive after police revised the timeline of the shooting after the attack.

Online sleuths claimed — entirely without basis — that Mr Campos was somehow involved in the massacre.

Some say they have even visited Mr Campos' house, and are poring through his online footprint in an attempt to make their theories stick.