By yesterday afternoon 30 people had contacted police through an 0800 number and by email.
More people contacted police overnight, said Detective Senior Sergeant Rhys Johnston today.
He said as a result of these calls and emails police have identified three more potential victims, all German.
Mr Johnston said police would like to hear from anyone who believed they were a victim and to give as many contact details as possible, such as landline and cellphone numbers, email addresses and Skype addresses.
"This information all helps us to maintain contact with potential victims," he said.
Police also asked potential victims to provide a photo of themselves, to help the inquiry team in its investigations.
"All information will be kept confidential and we will deal with victims sensitively and offer all appropriate support required."
A helpline number and email address had been set up so potential victims could get in touch with the investigation team.
To contact the investigation team call 0800 762 701, or send an email to operationsnap@police.govt.nz.