Known as Barnevernet, the agency provides a host of services to parents in need. But more controversially, it also removes children from their homes, placing them in institutions or foster families due to perceived shortcomings in their care, or if they are subjected to child-rearing methods perceived as violent.
This has led to what officials call "misunderstandings" with ethnic minorities, who often have different cultural codes and are overrepresented in having their children taken away, in a move some have branded "state kidnappings".
In this Scandinavian country of five million people, 1,665 children were removed from their parents' care in 2014, among them 424 with foreign-born mothers, agency figures show.
Jaquline Joseph and her husband Joe, both from Sri Lanka, suddenly had their three children taken away on November 14th, 2011, while they were living in Bergen, Norway's second-largest city.
Instead of coming home from school as usual that day, their two daughters, aged eight and 12, and their six-year-old son, were placed in emergency care after an anonymous tip about violence in the home.
Norwegian law bans all forms of corporal punishment of children, including slaps and spankings.
The Josephs found themselves accused of beating their children with a flag and a wooden ladle, of calling their eldest a "little shit" and "a bloody idiot", and of cutting their son's hand with scissors, court documents show.
They insist they have only ever given the children an occasional slap.
'Kidnap our own kids'
"Barnevernet has a tendency to make sweeping generalisations about all foreigners. According to them, because we're not Norwegian, we all beat our children with sticks or belts," Jaquline fumes.
At the end of a lengthy legal battle, the court largely sided with the Josephs, dismissing all the more serious allegations made by the agency and handing the pair a two-week suspended sentence for the slaps.
Ruling that the violence was a "cultural" issue which was "correctible", the court approved the "gradual" return of the two younger children.
But six months after the ruling, and frustrated that social services were dragging their feet, the Josephs fled Bergen for Oslo with the two younger children, leaving their jobs and their home behind -- and their third child in a foster home.
"We had to kidnap our own kids," said Joe Joseph, who had been employed as a machinist, while his wife did occasional work at a child daycare centre.
Stories like theirs make the headlines regularly, with their impact prompting protests around the globe.
On April 16th, thousands of people from Melbourne to Bucharest and even Hawaii came out to protest over the November removal of five children, including a three-month-old baby, from their Romanian Norwegian parents.
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Anti-Barnevernet protests were held in Oslo and over 50 other cities last month. Photo: Ole Berg-Rusten/NTB Scanpix
Marius and Ruth Bodnariu, who belong to Norway's Pentecostal movement, are accused of using corporal punishment on their children.
But the idea took hold that their children had been removed as a result of "Christian radicalism and indoctrination", prompting widespread protests by Christians around the world.
It's not always easy to discern fact from fiction.
While families can freely lay out their defence in the media, authorities must respect confidentiality, even when faced with far-fetched allegations.
"They say we kidnap the children of foreign parents because we want to increase the genetic diversity of the population. It turns my stomach to read some of the statements," said Kai-Morten Terning, secretary of state at the ministry for children and equality.
"Some criticisms deserve to be heard... but others are just untrue," he added.
Officially seen as a last resort, the decision to remove children from a family is not taken by Barnevernet, but by a three- to five-member social welfare board comprising a judge, a social worker and a lay person.
The board acts on the basis of Barnevernet's recommendations, but its decisions can be appealed within a regular court by family members who also have access to free legal help.
'A dysfunctional organisation'
Nonetheless, more than a hundred lawyers, psychologists and social workers wrote an open letter last year criticising Barnevernet as "a dysfunctional organisation that makes many erroneous evaluations with severe consequences".
Barnevernet fears a vicious cycle in which it gets a bad rap from high-profile cases sometimes based on false claims, which then leads to some foreign parents shying away from seeking help when they really need it.
The disputes have on occasion sparked diplomatic tensions.
In February 2015, Czech President Milos Zeman compared Barnevernet to the "Lebensborn", the welfare centres set up by the Nazis in order to boost the "Aryan race".
And relations between Norway and India soured several years ago over the case of an Indian couple who claimed their two children were taken away because they ate with their hands and the family slept in the same bed.
"It's not just about whether you sit on a chair or not, or whether you eat with your fingers or not," said a Barnevernet employee speaking on condition of anonymity.
"Very often, what it boils down to is that it's illegal in Norway to hit or slap, whereas it's not necessarily the case in other cultures," she said.
Changes promised but critics skeptical
In apparent response to the Barnevernet controversies, Norway recently announced a series of changes to how the organization operates, including a ratification of the Hague Convention that will mean that children who are taken from the parents in Norway can be placed with relatives abroad rather than in Norwegian foster care.
Some of Barnevernet's most vocal critics expressed measured hope about the changes.
"I am happy that the criticism from abroad is being taken seriously and Norwegian government tries to stop the injustice against families. However, I am quite afraid that this will help only in future cases and will not affect already known affairs," Czech MEP Tomáš Zdechovský said in a statement provided to The Local.
Human rights lawyer and frequent Barnevernet critic Marius Reikerås said Norway's announcement was welcome but unlikely to put a lid on the controversy.
"In my opinion and seen from a legal perspective, this statement from the government is a major break through. But it´s still more important than ever to keep up the pressure so that the people in charge actually fulfill their commitments," he said in a statement provided to The Local.