Constable Pete Reed wants to hear from witnesses to the incidents, which are believed to have occurred some time before midnight on Thursday.
"We believe it was a pre-planned operation, to get in [to the boxes]... It was definitely deliberate," Const Reed said yesterday.
The culprit would have spent some time opening the boxes, setting the fires and closing the boxes again, so there was a good chance they had been seen.
"There were plenty of people spilling out of the pubs on Thursday night," he said.
Both boxes were opened either with a key or a tool (they were not damaged) and the fires were set using the same type of kindling, indicating the same person or people were involved with both fires, Const Reed said.
Wanaka police extinguished one fire in a utility box outside Thunderbikes shop about midnight on Thursday but did not know about the fire in the utility box about 400m further down Brownston St, outside the Otago Daily Times office, until telecommunication engineers reported it yesterday morning.
Const Reed said the fires had damaged the intricate network of cables inside both boxes, causing many hours of work for the engineers and inconveniencing dozens of businesses within the area bounded by Helwick St, Brownston St, Dungarvon St and Ardmore St.
Initial reports were that some 40 businesses had been affected, but not many suffered long-term problems.
Telephone and internet connections were restored to some businesses during the day, with full restoration not expected until the end of yesterday, at the earliest.
Affected businesses included Aspiring Medical Centre, law firm Gallaway Cook Allan and surveying company Southern Land CKL.
Aspiring Medical Centre staff were too busy to comment when visited about 1pm because the outage had caused extra work for them.
Southern Land CKL director Vergne Wilson said Telecom had redirected all phone calls to his cellphone and his internet connection was restored by 11am.
"The phones and power do go out in Wanaka. It is part of life... But it potentially could've cost a lot of money," Mr Wilson said.
Checkout staff at New World Supermarket reported few problems as back-up servers had quickly taken over.
New World Supermarket health and safety manager Adrienne Taylor said it was business as usual, the tills were operating and there had been no apparent effect on trade or customers.
The ODT office at 82 Brownston St was among the worst affected and was still without phones or internet connections at 3pm.
Thunderbikes co-owner Matt Lewis said he was aware work was being done on the utility box but he had not realised the fire was deliberately lit.
The outage had not seemed to affect his business or others located in the same building on the corner of Helwick St and Brownston St.
• By yesterday afternoon, Telecom had fixed about 160 of 400 lines and intended to work through until all were restored.
