Gui Congyou, China’s ambassador to Sweden, was summoned Tuesday to the Swedish Foreign Ministry in Stockholm after a media interview in which he appeared to threaten local journalists who write critically about Beijing.

The dispute comes amid tensions between Stockholm and Beijing about the unexplained detention of a Swedish bookseller, anger in China at a “racist” TV skit on Swedish television about Chinese tourists, and continued threats of diplomatic and economic retaliation.

Gui has often found himself in the middle of these tensions, prompting some in Sweden to call for his expulsion.

In an interview Friday with Swedish state broadcaster SVT, Gui had slammed Swedish reporting on the Chinese government, accusing the journalists of “criticizing, accusing and smearing China” and implying retaliation.

According to a transcript posted by the Chinese Embassy, the ambassador compared the relationship between Swedish reporters and the Chinese government to a 100-pound boxer challenging a 190-pound boxer to a fight.

The heavyweight, “out of good will to protect the light weight boxer, advises him to leave and mind his own business, but the latter refuses to listen, and even breaks into the home of the heavy weight boxer,” Gui said, according to the transcript. “What choice do you expect the heavy weight boxer to have?”

On Saturday, Swedish Foreign Minister Ann Linde said the ambassador’s remarks were an “unacceptable threat,” adding that freedom of speech was protected by her country’s constitution. The Foreign Ministry summoned the ambassador on Tuesday, Agence France-Presse reports.

Relations between China and Sweden have been strained since Gui Minhai, a Chinese-born dissident scholar who held Swedish citizenship and lived near Gothenburg, went missing in Thailand in 2015. (Gui Minhai holds no relation to the Chinese ambassador).

Gui Minhai, who had lived most of his adult life in Sweden, had worked as a bookseller in Hong Kong, writing and overseeing the publication of books that cast a critical, gossipy light on the Chinese political elite.

The books were banned in China. Three months after his disappearance, he appeared on Chinese mainland television and confessed to a decade-old fatal drunken-driving accident in a seemingly scripted but incoherent monologue in which he also denied that he wanted any help from Swedish authorities.

Gui Minhai was later released but was rearrested in early 2018 while on a Beijing-bound train from Shanghai with two Swedish diplomats who were accompanying him as he sought medical treatment.

The case has remained a major problem for Sweden’s Foreign Ministry, which recalled its ambassador to China last year after reports that Anna Lindstedt had been involved in setting up an unusual meeting in Stockholm between Gui Minhai’s daughter and two Chinese business executives.

According to Angela Gui, Lindstedt had warned her that the Chinese government was taking a harsher line on activism surrounding the case and might “punish Sweden” if she continued to press for her father’s release publicly, while one of the business executives showed her a photograph of him with Ambassador Gui.

On Monday, Linde issued a statement noting it was the second anniversary of Gui Minhai’s rearrest. “There is no doubt that this matter, until resolved, is a burden to the bilateral relationship,” the statement read.

While many in Sweden were angry at the treatment of Gui Minhai, in China, something else had whipped up outrage toward Sweden: the alleged mistreatment of a Chinese family who was asked to leave the Generator Hostel in Stockholm when the tourists arrived a day earlier than their reservation.

Video of police removing a Chinese man from the hostel soon went viral on the Chinese Internet, while state media suggested the family had been beaten by police and abandoned in a graveyard, though Swedish accounts denied this.

“Why were the Chinese tourists treated so brutally and tossed at a graveyard in a desolate place by the police when they did not break any Swedish law?” Ambassador Gui told the Swedish newspaper Aftonbladet.

Swedish News, a satirical comedy show on SVT, later produced a mock tourism guide for Chinese visitors to Stockholm, poking fun at tropes of Asian people eating dogs and calling Chinese people racist.

The Chinese Embassy in Stockholm issued a statement that accused the show of trying to instigate racial hatred toward Chinese people.

“To think that such things could happen in Sweden, an advocate of ethnic equality!” the statement said.

Amid calls for a boycott of Swedish goods in China, SVT apologized.

But some analysts noted the role of the Chinese ambassador in Stockholm in fanning outrage against the segment and suggested it was part of a broader Chinese pushback amid tensions with Sweden.

Writing for the South China Morning Post, analysts Bjorn Jerden and Viking Bohman suggested Ambassador Gui, more experienced in diplomacy related to Russia, had taken an aggressive stance to try to “improve, or ‘correct,’ the debate about China in Sweden.”

After the Swedish branch of PEN International, a global association of writers, announced last year it would give a freedom-of-speech prize to Gui Minhai, Ambassador Gui warned that Sweden, a small country of 10 million people, would face consequences from China.

“First the image of Sweden among the 1.4 billion Chinese people will be damaged. Second, normal exchanges and cooperation will be seriously hindered,” he told Swedish Radio. “You are smart enough to know what I mean by ‘consequences.’ ”

In its report on its interview last week with the ambassador, SVT said he had frequently sent personal messages attacking reporting on China to reporters at several Swedish outlets.

SVT reported that at least three of Sweden’s eight parties in parliament wanted the ambassador declared a persona non grata, a view echoed by some journalists.

“Send the ambassador home,” the regional tabloid Varmlands Folkblad wrote Monday.