It emerged yesterday that a similar complaint was made to police about Harris late last year.
Detective Senior Sergeant Rhys Johnston confirmed that a male tourist approached police and his complaint was investigated.
"Mr Harris was interviewed, but ... there was insufficient evidence to show that something happened," he told the Herald yesterday. "Sadly that's common with the type of thing we are talking about here."
Mr Johnston could not discuss the specifics of the case but said the alleged offending was "very unique" and the investigation around it would be "significant".
After his arrest on Monday Harris appeared in the Kaitaia District Court and will remain in custody at the Northland Regional Corrections Facility at Kaikohe until his next scheduled appearance on Thursday.
Mr Johnston said the alleged victims were all males aged 18 to 26 from Germany, the UK and America. Since Harris' arrest he had received 15 phone calls and 12 emails from potential victims.
The Herald has learned that the alleged offending is claimed to have taken place in Harris' private residence at the lodge. There are several buildings on the property, including the residence, dorms and motels.
Mr Johnston said the alleged victims identified so far were all accommodated in rooms in the private residence.
"The owner's residence is the area that we've concentrated on," he said.
"On occasion he would have people staying there on longer-term situations, or if they were assisting in local work like fruit picking they would stay in rooms within the owner's residence. These are the people we are particularly interested in speaking to.
"That said, anyone that's got suspicions that something has happened to them or who has information is encouraged to come forward."
Police continued a search of the property yesterday. The lodge is open and operating and backpackers were still being picked up to go on tours to local attractions.
Lodge staff would not comment. But a tour operator who sent a driver to collect people for a trip to Cape Reinga said she spoke to them about the situation yesterday.
"I asked if they were doing okay and they said they were.
"They said they were still open for business."
Harris is the second owner of the Main Street Lodge to be arrested and charged with sex offending.
In 2008 Peter Kitchen, then 56, was jailed for 5 years after a jury found him guilty of raping and indecently assaulting a teenage girl.