Five men have been charged with blackmailing brothel and massage parlor owners in Auckland.
Police say three of the men, aged between 17 and 30, are Asian students.
They appeared in court last week on counts of demanding with menace, but reappeared on Wednesday to face the more serious charge of blackmail, which carries a maximum penalty of 14 years in jail.
Police say the charges relate to several incidents at massage parlours and brothels late last month and early this month.
They say proprietors and managers, mainly women, say they have been intimidated into paying the accused hundreds of dollars to ensure the safety of their staff and premises.
All five will reappear in Auckland District Court next month.