Claims that some aviation services staff at Sydney Airport were forced to sleep in makeshift "camps" between split shifts have been dismissed after an investigation.
Aerocare was accused in March of forcing some employees to sleep in a staff-only area near a baggage carousel in the airport's international terminal.
The Transport Workers Union (TWU) has accused Aerocare of trying to cover up evidence of the bedding used by workers.
But Aerocare says an investigation by the company, the Australian Border Force and officials from Sydney, Melbourne, Brisbane and Perth airports found "nothing to substantiate the existence of 'camps' where people are sleeping on site or any similar practices at any of these locations".
A review of Aerocare records stretching back three years found just one instance of an employee leaving personal items in an unauthorised part of Sydney Airport.
The employee was officially cautioned in April 2016 and continues to work for Aerocare.
Other items belonging to unnamed "other parties" were also found at the time, Aerocare said, but the area was cleared in response.
Staff from Aerocare claimed on ABC TV's 730 program last month that workers slept on the ground in the baggage handling area, as they often worked a three-hour shift and then had a long break before their next one started.
Images showing makeshift bedding on the ground was included in the program.
The TWU is urging Aerocare to release surveillance footage and digital records to prove they found no bedding in use at Sydney Airport's baggage carousel.
"The public were able to see in the media with their own eyes video footage and testimony from staff about appalling conditions, split shifts and low pay," TWU national secretary Tony Sheldon said.
"Instead of investigating this and the impact on safety at our airports, Aerocare has decided to try to cover it up."
Aerocare chief executive Glenn Rutherford rejected the accusation.
"There's nothing to show," he told AAP.
"Sydney Airport is certainly not interested in allowing that sort of thing happening, Border Force certainly wouldn't put up with that. It's a fabrication by TWU."
The claims emerged during Aerocare's ongoing talks with the TWU about a new pay deal for workers.