BEIJING — It is the high season for Chinese diplomacy — with past and present world leaders visiting Beijing over the past month — but the country’s foreign minister has been conspicuously absent.

Mr Qin Gang, supposedly the face of the country, has been out of the public view since June 25, missing important events such as a regional gathering of foreign ministers in Indonesia and a number of visits by senior American figures.

So far Beijing has been tight-lipped about his whereabouts, attributing his absence to unspecified “health reasons” despite growing speculation.

The prolonged absence of Qin, who was hand-picked by President Xi Jinping for the job just seven months ago, appears to be a huge embarrassment for China, diplomatic observers said.

They also warned that Beijing’s inability to shed the secrecy surrounding his disappearance has also raised many questions about China’s opaque decision-making.

Ms Yun Sun, director of the China programme at the Stimson Centre in Washington, said Beijing’s terse explanation is unconvincing.

“It appears that Beijing’s message is becoming more focused – that Qin has health issues,” she said. “Few believe it, but for China having an explanation that sticks and that it can stick to is important.”

Mr Qin was last seen in public when he met senior diplomats from Russia, Vietnam and Sri Lanka on June 25, according to the Foreign Ministry.

He was scheduled to meet the European Union’s foreign policy chief Josep Borrell last week, but Beijing abruptly cancelled the trip, saying Mr Qin was not available.

The cancellation without further explanation was a major “surprise if not embarrassment” to the Europeans, according to Mr Philippe Le Corre, a senior fellow at the Asia Society Policy Institute’s Centre for China Analysis.

On July 7, the foreign ministry was asked for the first time if health reasons were behind the cancellation, but its spokesman Wang Wenbin said he had “not heard about that”.

But just four days later, Mr Wang said Mr Qin would miss the Association of Southeast Asian Nations meeting in the Indonesian capital Jakarta because of “health reasons”, without elaborating.

Rumours about what happened to Mr Qin went into overdrive over the past weeks on domestic and foreign social media.

When pressed about Mr Qin’s mysterious disappearance on Monday, a different foreign ministry spokeswoman, Mao Ning, said she had “no information”.

But intriguingly, those questions and remarks regarding Mr Qin’s whereabouts were missing from the ministry’s website.

Mr Qin is still listed as the foreign minister on the official website of the Ministry of Foreign Affairs.

Also on Monday, the US State Department said it had been told that Mr Qin was “dealing with health issues” when China’s foreign policy chief Wang Yi stood in for the foreign minister at a meeting with US Secretary of State Antony Blinken at the Asean gathering.

“For any other country, this would be considered a huge diplomatic embarrassment. But in China, politics always dominate. Diplomacy is a second-rate activity, and the foreign minister is usually not that powerful, said Mr Le Corre.

The Communist Party is “preparing the Chinese public for some kind of an explanation — or a narrative, rather”, he said, adding that domestic concerns trumped international perceptions.

He noted Mr Qin’s rise — from deputy minister in charge of protocol, to ambassador to the US and then foreign minister — was relatively rapid, adding: “He is not your ‘usual’ foreign minister, so to speak. He is highly connected to the top.”

He also said: “I am not sure if Qin’s absence matters that much to foreign chancelleries. They are used to dealing with various offices which often do not translate well overseas. But if by any chance he was to come back, what would be his credibility as Chinese foreign minister?”

Dr Sari Arho Havrén, an associate fellow at the Royal United Services Institute in London, said Mr Qin’s case was a telling example of how the system operates.

“This is a guessing game. The Communist Party is far from being transparent and typically does not release information in this kind of situation, and although he has been missing for three weeks, which is a long time, we can only speculate,” she said.

“When it comes to China’s reputation and diplomacy, the case is considered an internal party affair, and I don’t think the Chinese authorities are really concerned about how this radiates, or looks, to the outside.”

Ms Sun also said the saga cast “much uncertainty and confusion over the consistency, stability and credibility of Beijing’s decision-making”.

“If a vice-national level leader can just disappear without much of an explanation, people find it difficult to trust and count on any Chinese leader or official and their positions,” she said.

Mr Alfred Wu, an associate professor at the Lee Kuan Yew School of Public Policy in Singapore, said Beijing’s failure to deny those rumours or clarify Mr Qin’s status was “an ominous sign” for his career and the country’s image.

He said this situation was not unprecedented, citing a mysterious two-week absence by President Xi shortly before his ascent to the top party role in 2012, adding: “It is another example of China’s obsession with secrecy.

“It is likely that the outside world may never know what actually happened to Qin if the Chinese authorities choose not to give an explanation for his absence, even if China’s image is at stake.”

But Assoc Prof Wu said some rumours about the foreign minister’s health and whereabouts had been allowed to circulate on the country’s tightly controlled internet, in contrast to US President Joe Biden’s recent comments calling Mr Xi a “dictator” which were totally off limits.

He suggested that Mr Qin’s absence and Beijing’s handling of it suggested China was becoming more authoritarian and “would doubtless add more uncertainty to China’s one-man politics, making it harder to ascertain and predict for foreign governments and investors”.

Mr Zhiqun Zhu, an international relations professor at Bucknell University in Pennsylvania, said the mystery would fuel negative perceptions of China’s opaque system.

“Qin’s disappearance has also affected China’s diplomacy at a critical juncture,” he said, citing European Union (EU) representative Josep Borrell’s cancelled trip to Beijing. “China needs to bolster relations with the EU now when bilateral ties are facing some headwinds.”

Sources told the South China Morning Post this week that Mr Borrell is “tentatively” expected to visit China in October after meeting Mr Wang, the foreign policy chief, at the Asean meeting.

Prof Zhu also said the choice of Mr Wang, who outranks Mr Qin in the Communist Party hierarchy, to fill in for Mr Qin in Jakarta and a meeting between Mr Xi and former Philippine president Rodrigo Duterte, underlined the importance China attaches to relations with Southeast Asia.

But Prof Zhu said the longer Mr Qin stays out of sight, the less likely it is he will re-emerge unscathed.

“Qin’s disappearance is sudden and highly unusual. By all indications, this does not seem to be a health issue, or we can assume that health is not a major reason for his disappearance,” he said. “But even if he returns, his reputation will have been damaged given all the rumours and speculation about him on social media.” SOUTH CHINA MORNING POST