Mr Smith said a 36-year-old man has been arrested on an unrelated matter and was in police custody. Mr Smith said police would not speculate on any further charges.
Mr Smith said LA had not yet been reunited with her family and she would be further assessed tomorrow.
Police were alerted to the teen's disappearance after her family received Facebook messages and texts on Saturday saying she was being held against her will and needed help.
Announcing this morning's development, officers thanked the public for their "considerable support".
A spokeswoman for the Tukerangi family said it was "awesome that she's been found" and "fantastic for the whanau".
Police yesterday refused to confirm whether the hunt for the 15-year-old was being treated as a kidnapping.
Detective Senior Sergeant Zane Smith said the focus was "on finding LA Tukerangi safe".
"I'll always support him"
Dani Whakatau, the sister of Dean says she's pleased the pair have been found.
"I'm happy that she can go home to her family - they have been worried as," she said.
"My brother, I feel for him and I know he's done the wrong thing by being with her, but it's good that they both handed themselves in together.
"We're just happy that they're both found, and now everyone can find out the truth and what really happened, and return her back to her family."
She had not yet spoken to her brother but stood by comments supporting him.
"Whatever happens to my brother, we'll just back him either way. We'll always be here to support him," she said.
"To LA, I hope she goes back to her family and carries on living her life."
Earlier this week, Ms Whakatau told NZME News Service the pair were in a relationship and had seemed happy together when they visited her in July. His criminal history, which includes charges of rape and kidnapping, was making the situation seem worse than it was, she said.
However, LA's family denied she was in a relationship with Whakatau, describing him as an "adopted brother" of their daughter's 16-year-old boyfriend.
A spokeswoman for the Tukerangi family said it was "awesome that she's been found" and "fantastic for the whanau".
Relieving principal for Te Whanau-a-Apanui School Alan Beeden was wrapped up in the drama last night.
Mr Beeden had his his first day at the school yesterday and went out for a meal with the head of the Board of Trustees, who happens to also be the sole charge police officer Whetu Haerewa.
The pair travelled from Te Kaha east to Waihau Bay for a meal.
"He said there'd been reports that the wanted car was in the area so he was on call," Mr Beeden said.
"He got a call to say the vehicle had been spotted in the area, so we back-tracked and sure enough heading in to town there goes the car."
Mr Beeden said his involvement in the police event ended before Mr Haerewa caught up with the wanted vehicle.
"He dropped me off at my accommodation and he went off on his job.
"He called this morning to say he'd made the arrest, so that's really good."
- With additional reporting from Alison King of the Rotorua Daily Post