Government inspectors have found 14 workers who could be receiving wages less than the new minimum hourly wage of HK$28 in the first week of the law coming into effect.
The suspected violations were identified from more than 800 inspections carried out by Labour Department officers in the past week.
Most of the companies targeted were in the cleaning, security and catering industries.
Secretary for Labour and Welfare Matthew Cheung Kin-chung said the bosses involved had been advised and would be investigated further.
'Our inspectors immediately explained the requirement of the law to the employers to ensure that the employees' rights are protected,' he said. 'The employers might not have known enough about the new law.
'Of course, if we find out they are doing it deliberately, we will take appropriate actions.'