The number of complaints against the Ministry for Vulnerable Children has doubled over four years, with a third being upheld.
Figures released under the Official Information Act show formal complaints jumped from 512 in the year ending June 2012 - when it was called Child, Youth and Family - to 971 in the year ending June 2016. The number stood at 699 for the nine months to the end of March 2017.
In total, some 4949 complaints had been received since 2012, with 1088 partly upheld and 565 fully upheld.
The high point was in the year ending June 2014 when complaints totalled 1080, with 242 partly upheld and 125 fully upheld.
"The number of complaints needs to be put into context," the ministry said in a statement.
"The ministry received over 63,000 care and protection notifications for the six-month period ... to December 2016 and ... had over 5000 children in the custody of the chief executive."
A Wellington woman, who to protect her teenage son's identity cannot be named, first laid a complaint over his care by social workers a couple of years ago.
"It didn't achieve anything really," said the woman.
Her son has now been in the ministry's custody for 10 months.
"It achieved a group of people sitting around the table ... basically telling me that they would work with me and my son to try and get us in a better position. We're no better off - in fact, we're worse off than what we were at that time," she said.
The woman, who is a senior manager in the public service, was not surprised at the relatively low number of formal complaints compared with the 63,000 interventions.
"Complaining ... is difficult and time consuming ... So the complaining's gone on the backburner and the focus is on getting the help my son needs. It's just too hard, it's too hard to try to navigate their system and their people."
She also said ministry staff treated her like scum and a criminal from the start, and the risk was that complaining could make that worse.
She doubted an independent complaints body would help because families would still face the daunting task of keeping a detailed record of all their correspondence over their complaint. She said her case ran to 1900 pages with countless emails.
Law Society family law chair Michelle Duggan believed a watchdog was needed, saying only a tiny number of people pursued their complaint to the highest level at the ministry.
Only 93 of 5183 complaints have proceeded to the chief executive's advisory panel since 2011, with 80 of those partly or fully upheld.
Other figures showed:
- In 23 complaints that went to the chief executive's advisory panel, compensation was paid out averaging $8800.
- The highest payout was $70,000 to individual members of a large family.
- Wellington had the highest number of advisory panel reviews, with six over the five-year-period.
- Most of the ministry's 93 offices had two or fewer complaints that went as high as the advisory panel.
"It's very hard to go to the organisation that you want to complain about with a complaint," Ms Duggan said.
Ministry for Vulnerable Children chief executive Grainne Moss has said the Children's Commissioner already independently monitored her social workers.
She also insisted the ministry now put children at the centre of all it did.
However, the unidentified Wellington woman said that did not square with the ministry's care for her son.
"They only know where he is because I told them when I rang them this morning. Yesterday they were not aware of his whereabouts. In fact, he'd been missing for a week... but that's not unusual."
The ministry took four months to release the information under the Official Information Act, instead of the statutory 20 working days.