A Polish diplomat was given a week to leave Norway after being declared a "persona non grata" on Monday, sparking a diplomatic spat between the two countries.
Norway's Ministry of Foreign Affairs spokesperson Ane Haavardsdatter Lunde said the diplomat, Slawomir Kowalski, had behaved inappropriately toward public officials and in his role as a diplomat.
However, Poland's Ministry of Foreign Affairs said the allegations were "unfounded."
In direct response, the Polish MFA added that it had decided to expel a Norwegian diplomat "on the principle of reciprocity and in line with international custom."
But what caused this row between two countries with such close ties?
How did this row begin?
Norway initially dismissed Slawomir Kowalski from his role in mid-January, calling upon Poland to recall him in three weeks, following reported complaints about his behaviour.
"The Ministry of Foreign Affairs has received repeated complaints regarding the consul, which have included allegations of threatening and at times violent behaviour towards public officials, and allegations that he has obstructed them in their work," the Norwegian MFA told Euronews via email.
"He has also refused to comply with police orders, and has been reported to the police on several occasions."
"In recent years, the issue of the consul’s behaviour has been repeatedly raised with the Polish Embassy in Oslo."
But Polish politicians say the expulsion was in relation to Kowalski's work with Polish families that had come into contact with Norway's controversial child welfare service, Barnevernet.
Szymon Szynkowski vel Sęk, the secretary of state for Poland's community abroad, wrote in a tweet in January that the Polish government "clearly appreciates the work of Consul Kowalski in defending the interests of Polish families".
He added" "The call for his dismissal is not justified."
What are the accusations of 'violent behaviour' in reference to?
While Norwegian officials have not confirmed any specific incidents of violence from Kowalski, there was one noted incident from June 2018, where police were called to a meeting Kowalski was attending after staff reported "feeling threatened."
Kowalski was due to assist at a meeting between a Polish family (at the request of the family) and child welfare officers in Hamar, in eastern Norway, but was escorted from the building after his arrival.
In a video of the incident, police officers are seen arriving at the building in Hamar, before Kowalski reminds them of his diplomatic immunity and his rights to assist the family in their meeting.
One police officer says: "Yes, that is fine, but [the staff] called from here and said that you threatened the employees here. They felt threatened. That's why we're here."
Kowalski can be heard rejecting the allegations and asking for proof.
Throughout the 15-minute video, the officers tell Kowalski he must leave the building himself, or be taken out. He eventually leaves.
The video only begins at the point at which police officers arrive at the building, and Euronews was unable to determine whether Kowalski had been aggressive toward staff prior to this.
Ordo Iuris, a group of coservative Polish lawyers, who published the video, said the footage showed that Norwegian authorities had "violated the international law".
"We are dealing with a serious misconduct by the Norwegian Police and Barnevernet officials," Ordo Iuris chairman Jerzy Kwaśniewski said in a statement.
"It is a direct violation of the consul's status guaranteed by the international law, of his right to communicate with Polish citizens and of his personal immunity."
"Despite being aware of the event and its importance, the Norwegian authorities still demand that the Polish consul be removed from the post, accusing him of 'aggressive obstruction of the officials' work and disobedience to the police'. The situation is an unprecedented provocation."
But Norway maintains that the expulsion was not due to Kowalski's work.
"For Norway this concerns the behaviour of a single diplomat in his dealings with Norwegian authorities," the Norwegian MFA told Euronews.
"It has nothing to do with the matters he has been working on."
What is Barnevernet and why is it controversial?
Norway's child welfare service, known as Barnevernet, has long been criticised for being quick to remove a child from its family, with some going as far to accuse the system of "kidnapping" children.
A number of cases have been heard in the European Court of Human Rights.
In 2016, thousands of people took part in protests around the world over the case of a Romanian-Norwegian family, whose children had been removed from their care.
Hillestad Thune, a Norwegian politician, human rights lawyer and former member of the European Human Rights Commission, said authorities and politicians "suffered from serious anxiety" when faced with criticism of the strict child welfare service.
"For years, I have argued that children in contact with the Norwegian child welfare services are subjected to abuse of authority and human rights violations that are not acknowledged, not registered, not excused and not used to correct practice," she added.
Norwegian psychologist Einar C. Salvesen said: "There is a lack of judgement, incompetence and abuse of the intention of the law when children are removed on the basis of punishment."
"The benefit of keeping the family together is obvious," he added. "What is needed from the child welfare services' side is to avoid unnecessary care takeovers and create a working environment that can both clarify the actual care and provide results in the form of learning and change."
Norway's MFA told Euronews it found Poland's retaliation "disappointing," and "unreasonable".
"We have not received any complaints regarding the behaviour of Norwegian diplomats in Poland from the Polish authorities."
"It is therefore unreasonable for Poland to respond by asking us to recall one of our diplomats from Warsaw, although it is entitled to do so."
In the meantime, a petition has been signed by almost 30,000 people calling for the Polish government to "not succumb to Norwegian pressure," and to allow Kowalski to continue his work.