hotel detective
house detective
house dick

It was the house detective, standing alone in the room, who had the next suspicion.

"You'll both have to wait here while I call the house detective."

I've got the house detective looking out for him, though, so Bobbi should be all right.

They returned to the lobby, where the house detective left them.

A girl there was shaking her head, when one of the house detectives stepped over.

He followed the three, and spoke in a low tone to the house detective.

They followed the house detective to a room near the end of the corridor.

He grabbed a bell boy by the arm, and sent him after the house detective, who was at the other side of the floor.

A call to the house detectives - to the police - telling them of the situation.

The bell boy would soon be back with the house detective.