Police are investigating 19 reported burglaries at homes in Canterbury that may have happened when people were evacuated from their homes.
The initial magnitude 7.5 earthquake was 16km deep and struck near Hanmer Springs at 12.02am.
Canterbury District Commander Superintendent John Price said some of the burglaries may have occurred prior to the earthquakes, but a number of homes were definitely broken into while their occupants were evacuated due to tsunami warnings.
Mr Price said it was extremely disappointing to see people taking advantage of a traumatic event and the police were now increasing the numbers of staff carrying out patrols in the region.
He said the burglaries were at both residential and commercial properties.
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Matt Mill of New Brighton, with his wife Melissa and their four children including their wheelchair-bound daughter, left home about 2am after they learned of the tsunami risk, he said.
Tsunami warnings were later reduced to a marine and land threat warning, particularly for Chatham Islands and the region between Blenheim and Banks Peninsula.
When the family returned just after 6am, Mr Mill's work vehicle was missing and a further check revealed their home had been burgled, he told RNZ.
Items taken included electronic and sports equipment and a battery for their daughter's hearing aid, which would be of no use to anyone else.
"One thing that has gutted us the most is that they took my daughter's hearing system, she'd only just got it.
"[She is] pretty upset, she hasn't got out of the car yet knowing someone's been through our house, through her bedroom.
"They've taken even her necklaces and stuff that are worth something to her, but not much to anyone else."