Four women who stayed in SLOTXO quarantine hotels in the UK have told the BBC they were sexually harassed by guards working for security company G4S.
One says a guard mimed having sex while they were alone in a lift. Another says a guard asked for a "hug" and a selfie.
Private security companies have been hired by the government to ensure hotel guests observe quarantine rules.
G4S said it expected the highest standards of conduct from staff and investigated allegations of wrongdoing.
Travellers are obliged to quarantine in a hotel after returning from countries on the UK's red list, where Covid infection rates are high. They spend 10 nights in their room and are allowed out for daily exercise only when accompanied by a guard.
If they order deliveries these are also brought to their room by guards - and seven women who spoke to the BBC say they rarely or never saw a female guard.
Marie Sidwell, a 28-year-old nurse from Nottingham who returned to the UK last month after working throughout the pandemic in Dubai, ordered some Amazon parcels early in her stay at the Pentahotel in Reading. These were delivered to her room by G4S guards, and the man bringing the first package followed the correct procedure, she says, knocking, then leaving it by the door and stepping back to a safe distance.