The Portugal Ministry of Foreign Affairs faces mounting international pressure to intervene after a dual Portuguese-Chinese national entered his 11th month of detention in Macau, sparking an imminent appeal to the United Nations Working Group on Arbitrary Detention and raising uncomfortable questions about Portuguese judges serving in the territory's national security courts.
Au Kam San, a former pro-democracy legislator and Portuguese citizen, was detained in July 2025 and will stand trial in Macau's Judicial Base Court on charges of state subversion and colluding with external entities to undermine national security. As of June 2026, his family has not spoken to him once since armed officers appeared at their home without warning, detaining first his wife and then Au himself after searching their residence.
Why This Matters
• Diplomatic friction: Portugal's consular access to a dual national has been blocked, raising questions about the 1987 Sino-Portuguese Joint Declaration guaranteeing freedoms until 2049.
• Legal precedent: Au Kam San is the first person prosecuted under Macau's revised 2023 National Security Law, setting a benchmark for future cases.
• Judicial ethics: International lawyers are now urging the Portuguese Conselho Superior da Magistratura to reconsider sending judges to a system where defendants are held incommunicado for nearly a year.
The Silent Detention
Cherry Au, the activist's daughter who has lived in the United Kingdom since age 13, described the arrest as surreal. "We never imagined something like this could happen in Macau. In Hong Kong, maybe. In Macau, it was absurd to even think about. That's what my father believed. He said, 'There's no way this will happen. Macau is different,'" she told news agency Lusa via video call.
For 340 days, the family has received no direct communication from Au Kam San. A court-appointed social worker provides only cursory updates: he is eating well, he is fine. Cherry attempted to hire a private lawyer in Macau, but the attorney was denied access to the defendant and ultimately refused the case, citing pressure from local authorities. She does not know the identity of the court-appointed defense counsel mentioned in the indictment order.
The 2023 revision of Macau's National Security Law permits judges to prohibit pretrial detainees from receiving visitors to prevent the disclosure of state secrets. Michael Polak, director of Justice Abroad, a UK-based human rights litigation organization representing Au's family internationally, called the detention "quite clearly arbitrary."
"I have no doubt the UN Working Group on Arbitrary Detention will reach this conclusion when we submit a complaint regarding this case," Polak said. The WGAD, under the authority of the UN Human Rights Council, has regularly criticized detentions in mainland China and Hong Kong. In 2024, the body ruled that Jimmy Lai Chee-ying, the Hong Kong pro-democracy media magnate, was detained illegally and arbitrarily; he was subsequently sentenced to 20 years in prison for collusion with foreign entities.
What This Means for Portuguese Nationals
The case exposes the practical limits of Portuguese consular protection for dual nationals in Chinese-administered territories. Despite Polak's assertion that the Portuguese Consulate in Macau requested access and was denied, the Portugal Foreign Ministry issued a contradictory statement: "There has been no official notification regarding the detention of dual national Au Kam San, nor has any request for consular support been received."
The ministry explained that under the Vienna Convention on Consular Relations and Portuguese consular regulations, diplomatic posts activate protection mechanisms only at the request of the detainee, respecting the individual's wishes. It added: "Given that he is also a Chinese national, it is not excluded that the procedural procedures applied by local authorities are limited to his status as a Chinese citizen." The consulate general in Macau continues to monitor the case, the ministry stated.
China does not recognize dual nationality. For Portuguese passport holders with Chinese heritage—particularly the thousands who obtained citizenship before Macau's 1999 handover—this case demonstrates a critical vulnerability: Chinese authorities may refuse consular access based on Chinese nationality alone, regardless of Portuguese citizenship status. If you travel to or reside in Macau or mainland China, consular protection from Portugal may be unavailable.
Prime Minister Luís Montenegro visited Macau in September and met with Chief Executive Sam Hou Fai but admitted he did not discuss Au's detention, defending the need for "necessary discretion" and "some restraint." The two leaders met again in April in Lisbon, yet nothing was publicly said about the former legislator's imprisonment.
The 1987 Agreement Under Strain
Cherry Au argues her father's detention violates the Sino-Portuguese Joint Declaration of 1987, the treaty that framed Macau's transition to Chinese administration in 1999. That agreement stipulated the territory should maintain fundamental rights and freedoms—including freedom of expression—during a 50-year transition period ending in 2049.
"The Chinese government should not tamper with these rights or change all the laws to fit their ideology. So it's very frustrating to see Macau going in that direction, and losing everything that's in our identity," Cherry said.
For three decades, Hong Kong and Macau were the only places on Chinese soil where the June 4, 1989 Tiananmen Square crackdown was commemorated with public vigils. Au Kam San was one of the organizers in Macau. In 2020, Cherry and her sister Christy were detained for livestreaming a private vigil via social media. She has not returned to Macau since her father's arrest, citing family concerns for her safety.
EU Involvement and the Diplomatic Calculus
According to Polak, European Union officials raised Au's case when Sam Hou Fai visited Brussels in April. "They are involved in the case. They are concerned with the case," he said. Neither the Macau government nor the EU Office in Hong Kong responded to requests for comment.
Polak believes one trigger for Au's arrest was meetings with the EU office in Hong Kong and Macau, led by British diplomat Harvey Rouse. In November, Rouse stated he had expressed "concern about political issues" in a meeting with Macau's then-Secretary for Economy and Finance, Anton Tai Kin Ip.
"China has demonstrated before that it cares about the opinion of the international community, especially the European Union. There is an enormous bilateral trade relationship," Polak noted.
More than 400 people have been detained in national security cases in Hong Kong since Beijing imposed its security law in response to the sometimes violent anti-government protests of 2019. Au Kam San is the first such prosecution in Macau.
Should Portuguese Judges Serve National Security Courts?
Polak has called on the Portuguese judiciary and the Justice Ministry to reconsider their involvement in Macau's legal system. "The Portuguese judiciary will have to ask itself, the Justice Ministry will have to ask itself: 'Can we be part of this system (...), where someone can be arrested and held incommunicado for something they said?'" he asked.
The situation in Macau, he argued, mirrors Hong Kong, where most foreign judges have concluded they cannot continue to operate in such a system. Several, including UK and Canadian judges, have resigned. In 2024, British judge Jonathan Sumption warned that the rule of law is "in danger" in Hong Kong due to pressure from Beijing.
"Without access to an independent lawyer, if we're prosecuting people for things they said about democracy, is it possible to call it justice? Or is it just a political system of persecution?" Polak said.
In March, the Conselho Superior da Magistratura (Portugal's judicial council) opened recruitment for two judges to work in the civil courts of Macau's first-instance tribunals. Currently, Jerónimo Alberto Gonçalves Santos is the only Portuguese judge serving in Macau, at the Court of Second Instance, after judge Rui Ribeiro brought forward the end of his special commission from May 2026 to October 2025.
In 2024, the CSM rejected the continued service of Carlos Carvalho, a Portuguese judge at the Court of First Instance who had served 16 years in Macau and had been invited by the territory's Independent Commission for the Nomination of Judges to extend for another two.
Portugal and Macau maintain a judicial cooperation agreement ensuring continuity of Portuguese magistrates—judges and prosecutors—in the territory, supporting the legal system of Portuguese origin. Yet a 2018 legal amendment limits trials in state security cases to judges with Chinese citizenship, effectively excluding foreign magistrates.
The Trial Ahead
The indictment order approved the prosecution after reviewing a defense motion challenging the charges. The case has now been transferred to the Criminal Court of the Judicial Base Tribunal, where a presiding judge will set a trial date. Proceedings may be held behind closed doors under the national security law.
The court stated that Au's court-appointed defense attorney was "officially designated and previously recognized by the defendant" and that "his procedural rights have been guaranteed under the law." Cherry Au disputes this: "No matter how many emails we send and whatever department we contact, they all ignore us," she said.
Polak assessed the likelihood of a fair trial as "very small," given the difficulty of finding a lawyer "brave enough to stand up and challenge the charges against him."
The case underscores a broader tension: as the 2049 deadline for the end of the "One Country, Two Systems" framework approaches, the space for dissent in Macau—long seen as more politically docile than Hong Kong—appears to be shrinking rapidly. For Portuguese citizens with ties to the territory, Au Kam San's prosecution is a stark reminder that dual nationality offers little protection when Beijing decides to enforce its vision of national security.
