Police officers carried out an undercover sting at hotels across South Yorkshire as part of a week of action to tackle child sexual exploitation.
The operation saw an adult man - played by a police officer - try to book a room with a teenage girl, played by a police cadet.
It comes after all hotels had received an internationally-recognised training package to help them spot the warning signs of potential child sexual exploitation.
In Sheffield five hotels were visited and at all five, the officer and cadet were refused rooms and challenged by hotel staff.
The operation in Barnsley saw seven hotels visited and access was denied at six out of seven hotels. The remaining hotel received advice and refresher training from officers about warning signs of potential sexual exploitation.
In Doncaster, the operation went to 13 hotels and of those, seven refused access to the officer and cadet as they had suspicions about child sexual exploitation. Six premises did not intervene and were given immediate feedback by police officers. All hotels will also receive written feedback on the operation.
Rotherham carried out a similar operation, where a number of hotels were visited and two failed to report their concerns to officers.
Det Ch Insp Melanie Palin, force lead for child sexual exploitation, said: “Overall, the operations across our region went very well and I am grateful to the officers and young cadets who gave up their time to take part in this exercise.
“Operations like this are massively important – we work closely with hospitality and other industries to make sure as many people as possible have the necessary training to spot potential signs of child sexual exploitation and know how to take action to safeguard children.
“This is part of our ongoing commitment to tackling this crime, working in partnership with businesses, agencies, communities and the wider public to protect and safeguard our young people from harm.
“While there has been concerted and targeted activity over the last week in the run-up to CSE Awareness Day, this is a continuous programme of activity and similar operations will be run in the future.”