Three women and a man were charged after it was revealed that the former head of the national security department of the police, Frederic Choi, had been caught visiting the unlicensed massage parlour on Johnson Road in Wan Chai in March.
Masseurs Li Yi-qing, 36, Nguyen Thi Thu Huong, 34, Zhang Ming-fang, 35, as well as Wu Ping-hung, 62, denied charges including managing or keeping a vice establishment or an unlicensed massage parlour between October 28 last year and March 19 this year.
Magistrate Ivy Chui adjourned the hearing to October 21 for a pre-trial review.
Police said earlier they had wrapped up an investigation into Choi and concluded that the senior assistant commissioner had not been engaged in any unethical or illegal behaviour.
Choi took up his new role as the director of the police personnel and training department in mid-August.