He said that number continued to grow today.
"The number keeps going up ... Some of that is people providing us with background information ... Some of them are also potential victims that we will be getting back in touch with."
Harris had been running the lodge for two and a half years, but police would be looking into his earlier background as part of the investigation.
Before moving to Kaitaia, it was understood Harris lived in Auckland, Mr Johnston said.
At this stage there was no indication Harris had offended elsewhere but investigations would continue, Mr Johnston said.
"What he has been up to is certainly going to part of our investigation, where he has been, where he has been employed and whether there is other people that have been put at risk," he said.
"We know that we do have a certain number of victims because of the material we have recovered, so we have quite a bit of work in front of us, just to identify them and get in touch with them."
He said police would offer victims support, whether that was through victim support staff or specialist referrals.
"Some of these people are all over the world and that provides some logistical challenges for us, but we are working our way through it."
Harris appeared in Kaitaia District Court yesterday where he was remanded in custody until September 18.
The lodge offered backpacking facilities, hotel units and, on occasion, longer term accommodation in the owner's residence.
Mr Johnston said potential victims who have contacted police were German, English, Scottish and American, as well as New Zealanders.
"Callers are concerned about whether something has happened to them and we want to be able to provide these potential victims with the right support as well as gather the evidence necessary."
He reassured tourists and local residents that a thorough investigation was being carried out.
"The community has trust and confidence in the local police and know complaints will be taken seriously and police will do something about it," he said.
"The local community welcomes and values the many tourists it gets in the far north.
"These are very unusual allegations and we will not let them impact on the reputation of a region known for being a favourite destination for overseas visitors."
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.