Los Angeles: The company that runs the Mandalay Bay Resort and Casino has disputed the timeline offered by Las Vegas police for the October 1 mass shooting at the hotel.

It suggested that very little time had elapsed between when gunman Stephen Paddock shot a hotel security guard and when he started firing on a concert crowd outside.

Two hotel employees had called for help and reported that gunman Stephen Paddock sprayed a hallway with bullets, striking an unarmed security guard in the leg. Credit:AP

The police timeline indicates that six minutes elapsed after security guard Jesus Campos was shot outside Paddock's hotel room door before Paddock fired his first shots at the crowd, but MGM Resorts International managers said on Wednesday they are "now confident" that the timeline is "not accurate".

"We know that shots were being fired at the festival lot at the same time as, or within 40 seconds after, the time Jesus Campos first reported that shots were fired over the radio," the company said in a statement.