"This person is helping police with our inquiries," a spokesman said.
This morning, investigators had not made any arrests, but said there was no risk to the public.
Neighbours who lived on the quiet street said they did not see or hear anything at the time of the burglary.
Perry Rau, whose flat shares a wall with the adjacent unit, said he was woken by police lights and sirens just before 10pm and was surprised when told what had happened.
"It's just a whole lot of seniors at home," he said.
The man who lived at the address was a popular figure in Tuakau.
"Everybody you talk to in town knows him. He's been a drinking buddy with people in town for years," Mr Pau said.
A friend of the man whose home was broken into said she was surprised a block of pensioner flats was targeted.
"I'm surprised elderly people, kaumatua, are getting robbed. Usually it's other other houses down Jellicoe getting robbed or attacked."
Another neighbour, Shirley Tetzlaff, 80, has lived three flats down from the address and has known the elderly occupant "for years".
"He's a nice chap. He's got plenty of friends," she said.
She learned of what had happened only when another neighbour visited her this morning.
"I didn't hear a thing. I had the drapes closed and the TV going."