There are 168 needy families waiting for social housing in Northland and others don't make it to the list because the Government has changed the criteria, he said.
Since 2011 HNZC has sold 81 Northland properties and currently has 28 on the market, but could not provide the Advocate with prices or GVs, saying to extract the information would be difficult and also citing "commercial sensitivity".
"Housing New Zealand is claiming its sales information is sensitive because it does not want to reveal that information to New Zealanders," Mr Twyford said. "They are embarrassed that they are selling off houses in an area of high housing need at cut prices."
The state house sell-off was "pure ideology, and a shambles from start to finish," he said.
"First they claimed they were the wrong place and the wrong size, then it was that local community housing providers could manage them better, yet now they are selling them off to overseas companies, banks and property speculators after major community housing providers like the Salvation Army pulled out," Mr Twyford said.
The Northland sales apply to individual properties in mainly rural locations, not multiple properties in one area.
The records obtained by Labour show that last year a house at Cable Bay sold for $205,000, or $25,000 under its $230,000 GV. Another house at Cable Bay sold for $200,000 (GV $225,000); one at Kaikohe for $120,000 (GV $132,000); one in Kaikohe for $80,000 (GV$119,000); one in Whangarei for $98,000 (GV $126,000).
Only three sold for more than their GV; at Kaeo, Kaitaia and Dargaville.
The Advocate does not have sales figures for the 50 houses sold between 2011 and 2014. In that time the agency built or bought only five replacements, with a further four planned.