China’s abrupt removal of Qin Gang as foreign minister did not stop the questions that had dogged Chinese officials in the month since he vanished from public view: Where is Mr. Qin? Does he have health issues? Is he under investigation?

Representatives of the Foreign Ministry have struggled to respond when pressed by reporters, repeatedly saying that they had no information to provide. After China replaced him on Tuesday, nearly all references to Mr. Qin were scrubbed from the ministry’s website, an unusual erasure that has only deepened the intrigue. On Thursday, asked by a reporter if China had been transparent about Mr. Qin’s ousting, a spokeswoman lashed out at what she called “malicious hype.”

For a department tasked with speaking to the outside world, the Chinese Foreign Ministry’s floundering response to the disappearance of one of its own top officials highlights the weakness of China’s diplomatic apparatus under President Xi Jinping. Mr. Xi, China’s most powerful leader since Mao Zedong, has concentrated power under himself and enforced secrecy in an already highly opaque system, no matter the cost to China’s international image.

Mr. Xi has diminished the sway of the Foreign Ministry, analysts say, as he’s pursued an increasingly assertive, and some say risky, foreign policy.

“The larger foreign ministry’s bureaucracy has been losing its influence over foreign policy for most of the Xi era, with decisions on key issues like Taiwan or the U.S. being made within the Party and dominated by Xi,” said Jude Blanchette, who holds the Freeman Chair in China Studies at the Center for Strategic and International Studies in Washington.

Mr. Xi has presided over China’s worst bilateral relationship with the United States in decades; he has aggressively pressed China’s claim over the self-governed island of Taiwan; and in the face of widespread criticism, he remains committed to supporting Russia despite its invasion of Ukraine.

Mr. Xi is also thought to be responsible for Mr. Qin’s meteoric rise, allowing him to overtake more experienced diplomats, in being named foreign minister late last year after serving only 17 months as China’s ambassador in Washington.

“The basic parameters of Beijing’s foreign policy are pretty well fixed, and so a single personnel change, especially Qin Gang’s, won’t adjust this trajectory,” Mr. Blanchette said. “Qin Gang is no Henry Kissinger.”

In a sign of how bizarre the circumstances surrounding Mr. Qin’s removal are, the foreign minister’s page on the Foreign Ministry’s website only reads: “Information updating …” Searches with his name turn up no results, as if he never existed within the bureaucracy. That means no references to his past meetings with his foreign counterparts, his speeches and official visits overseas.

The erasure harkened back to the days of Mao Zedong, when political enemies were expunged from photographs and official documents. It also suggests he has unexpectedly run afoul of the Communist Party leadership and not succumbed to a health issue as had been suggested by the Foreign Ministry earlier this month when asked why he wasn’t attending a meeting of Southeast Asian nations in Indonesia.

On Wednesday, the Foreign Ministry looked flat-footed again when its spokeswoman, Mao Ning, was unable to provide any answers to at least 20 questions about Mr. Qin at a news briefing in Beijing.

Ms. Mao repeatedly told the reporters to refer to Chinese state media for more information, and briefly chuckled when a reporter appeared flabbergasted by her insistence that the situation was “very clear.”

An official transcript of the briefing omitted any questions about Mr. Qin, adding to the Orwellian flavor of the controversy.

“All questions are covered up!” a user of Weibo commented under a video of the news briefing.

“She can’t say anything as a spokeswoman,” noted another user.

The fumbling response, in part, reflects how the ministry is charged with explaining and implementing the wide-ranging goals and whims of the party’s leadership without necessarily being granted access to its thinking.

Sometimes the message from the leadership is clear. The ministry’s adoption in recent years of an aggressive brand of statesmanship known as “wolf-warrior” diplomacy mirrored Mr. Xi’s calls for China to be more assertive on the global stage.

Other times, Chinese diplomats have had to hedge. Joseph Torigian, an assistant professor at American University in Washington who studies elite politics in China, recounted a story he was told by a party historian: An official at the Foreign Ministry in the 1980s who was asked to analyze whether China should mend ties with the Soviet Union once wrote two reports staking opposite positions because he did not know yet which one China’s leader at the time, Deng Xiaoping, would favor.

“The whole game is to adhere as closely as possible to what the leader wants,” Mr. Torigian said. “In that sense, the Foreign Ministry has always been an organization that executes policy and not an organization that deliberates policy.”

Mr. Qin has been replaced by his predecessor, Wang Yi, a senior diplomat who has spent the last few weeks holding meetings with senior foreign officials, including John Kerry, President Biden’s climate change envoy, and Josep Borrell Fontelles, the European Union’s top diplomat.

As a member of the Politburo, the council of China’s 24 most senior officials, Mr. Wang should have more access to Mr. Xi than previous foreign ministers, though that doesn’t guarantee more influence in policymaking.

Whether Mr. Wang is just a placeholder also remains to be seen — another question Ms. Mao declined to shed any more light on — but he returns to his former position as China is bidding to play a bigger role in global affairs than ever before, with Mr. Xi at the center of those efforts, rather than Chinese diplomats.

This week, Mr. Wang has been in South Africa and Turkey, where he has called on countries in the global south to resist Western hegemony and to forge more cooperation.

Mr. Xi has sought to reshape the world order, touting a series of global initiatives around development, security and culture as an alternative to the “rules-based order” championed by the United States after World War II.

“It’s really hard to put big wins on the board in terms of foreign policy,” Mr. Torigian said. “So one of the things Mr. Xi can focus on instead is burnishing his image as statesman.”

Olivia Wang contributed research.