A Family Court judge alerted the head of Oranga Tamariki to an assault accusation that had not been investigated.
Papers released under the Official Information Act show Grainne Moss later told Judge Tim Black that her agency and the police did not appear to have co-operated properly on the case.
The documents also show that since the agency was set up in April last year, Family Court judges have raised concerns directly with chief executive Grainne Moss on 10 occasions.
Several Family Court lawyers have told RNZ that direct contact from a judge to the head of Oranga Tamariki is normally considered unusual.
In three of the 10 cases, from the Hutt Valley and Christchurch Family Courts, extracts of what Mrs Moss wrote back to the judge (in all three cases, Judge T M Black), are included.
So far the court has not responded to RNZ's requests to release what Judge Black sent Mrs Moss in the first place.
"I am grateful to you for bringing this matter to my attention," Mrs Moss wrote to the judge on 18 April this year.
"I was concerned to learn that no investigation of the allegation of assault made in November 2017 had occurred and that Oranga Tamariki and Police did not seem very joined up on this matter."
She goes on to say it had now been investigated and the court updated.
The OIA does not show what the result of the investigation was, or give any further details of the case - but typically the Family Court hears about assaults on children.
In another Hutt Valley case from April this year, Mrs Moss told Judge Black she understood the importance of complying with his directions.
"I share your concerns regarding the impact for [redacted] and the Court by not meeting the required timeframes ...and understand the potential effect of delays for children and young people and the court process."
The regional manager for the Hutt, Grant Bennett, had explained to her the cause of the "poor response" (the OIA does not detail what it was) - and she went on to say they had put in place systems to "ensure this doesn't occur again".
Yet three months later, on 31 July, the chief executive once again responds to new concerns from Judge Black, this time relating to the Christchurch Family Court.
The agency's regional manager there "has looked into the practice of Oranga Tamariki staff in relation to the case in question". No more details are given.
In seven of the 10 cases of judges directly contacting Grainne Moss, very little information is given in the OIA, except to say that "in some cases, the Judge's Minute requests that other reports or court documents be provided to the Chief Executive along with the Minute".
"It is not yet possible to draw trends from the concerns raised so far" by the 10 approaches by judges, the agency said in its OIA response.
Social workers were involved with thousands of Family Court hearings a year, it said.
"We recognise the importance of meeting the court's expectations ...We value feedback from the judiciary and use this to improve the ways in which we work with the courts."
The agency said in February two deputy chief executives talked about workload pressures with the Principal Family Court Judge, and they agreed on a way judges could promptly raise concerns with regional managers or the chief executive. They added, they aimed to hold another meeting soon to review how this was going.
A second OIA response illustrates some of the work pressures.
It shows staff turnover at Oranga Tamariki's Lower Hutt office was 32 percent in 2016 and 20 percent last year, although quite a few were retirements not resignations.
Upper Hutt was worse with a 56 percent turnover two years ago, and 43 percent last year - so almost half its 12 staff resigning in each of those years.
That had stabilised, the agency said. Also, it had created 13 new social worker positions across the Hutt Valley since April last year and boosted Upper Hutt's numbers to 16.4.
The Hutt now has two staff whose only job is to prepare custody and section 132 reports for the court.
The OIA shows 21 of these reports weren't done on time in Upper Hutt in the nine months to March, compared to eight in Lower Hutt and just one in Waitakere.