He said the woman had shifted from Seoul earlier this year, after moving to South Korea in 2018.
"What made it harder to find her was that she was not living in a residence that was under her own name. She was kind of a long-term guest in a property that was under somebody else's name," Borowiec said.
As the woman was taken into custody by Korean police, she told reporters she was innocent.
Borowiec said the case has attracted a lot of attention in South Korea.
He said in the coming days, Koreans will grapple with the possible shame and harm this story could bring on the country.
Borowiec speculates that the extradition process would go ahead expeditiously.
"It seems the two countries are pretty much on the same page in wanting to as quickly as possible find answers as to what happened here," he said.
Clendon Park tragedy
In August 2022, Auckland police discovered human remains at house in Clendon Park.
Police were alerted to the discovery after a family bought an abandoned storage locker in an online auction that unbeknown to them contained human remains of children believed to be aged between 5 and 10.
Earlier in the week, NZ Police requested an arrest warrant for the woman to the Korean Courts, under the extradition treaty between New Zealand and the Republic of Korea.
Counties Manukau CIB Detective Inspector Tofilau Fa'amanuia Vaaelua said New Zealand police had applied to have the woman extradited back to New Zealand to face the charges and had requested she remain in custody while awaiting completion of the extradition process.
Police suspect the woman arrested could be the mother of the two victims, because her past address in New Zealand was registered to the storage unit where the suitcases had been left.