She was once one of China’s most feared journalists, roaming the country uncovering stories about police brutality, wrongful convictions and environmental disasters. But these days, Zhang Wenmin struggles to be heard.

The police intimidate Ms Zhang’s sources. The authorities shut down her social media accounts. Unable to find news outlets that will publish her work, she lives largely off her savings.

“The space for free speech has become so limited,” Ms Zhang said. “It’s now dangerous to say you are an independent journalist.”

China’s investigative reporters once provided rare voices of accountability and criticism in a society tightly controlled by the ruling Communist Party, exposing scandals about babies sickened by tainted formula and blood-selling schemes backed by the government.

But under President Xi Jinping, such journalists have all but disappeared, as the authorities have harassed and imprisoned dozens of reporters and as news outlets have cut back on in-depth reporting. One of the most glaring consequences of Mr Xi’s revival of strongman politics is that the Chinese press is now almost entirely devoid of critical reporting, filled instead with upbeat portrayals of life in China under Mr Xi.

Critics call it the “total censorship era.”

“We’re almost extinct,” said Liu Hu, a reporter from the southwestern province of Sichuan who was detained for nearly a year after investigating corrupt politicians. “No one is left to reveal the truth.”

Since rising to power in 2012, Mr Xi has transformed China’s media landscape, restoring the primacy of party-controlled news outlets while silencing independent voices. He has said that the mission of the news media should be to spread “positive energy” and to “love the party, protect the party and serve the party.”

Mr Xi’s crackdown on journalists has left China, with its nearly 1.4 billion people, in what sometimes seems like an information vacuum. At a time when world leaders are asking what kind of superpower China will be, public discourse within the country is remarkably monolithic. Instead of policy debates, there are calls in the Chinese press to defend China’s socialist system. Instead of scrutiny of Chinese leaders and institutions, there are paeans to Mr Xi and the party.

“The government has made its citizens ignorant,” Mr Liu said. “The public’s eyes are blind, their ears are deaf and their mouths have no words.”

When Donald Trump criticises China, his words rarely appear in the mainstream Chinese press. A rapidly expanding list of topics is off limits to all but the party’s main official media outlets, among them the trade war with the United States, the #MeToo movement, gene-edited babies and the spread of African swine fever.

Clayton Dube, director of the US-China Institute at the University of Southern California, said Mr Xi was sending a message that only the party had the power to criticise.

“Rather than seeing investigative journalism as an aid to remedying social ills and improving governance,” he said, “Xi’s party-state sees it as a threat to social stability.”

An exodus of journalists has alarmed free speech advocates. Xue Lei quit his job two years ago as a reporter for the Beijing Youth Daily, a party newspaper, to work in public relations at a technology firm. He said he had grown tired of censorship orders and the pressure to produce clickbait instead of investigative pieces.

“Issues that used to be covered a lot suddenly became restricted,” he said, pointing to stories about crime and corruption. “Sometimes you wouldn’t even know where a censorship order was coming from.”

Economic considerations have also contributed to the disappearance of in-depth reporting. Many news outlets in China, like those elsewhere in the world, are struggling with steep losses in print advertising revenue and have eliminated investigative reporting teams, which typically require more time and resources and produce fewer stories.

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As traditional news outlets shed staff, the rise of online media in China once inspired optimism about the future of in-depth reporting. But Mr Xi’s campaign has also targeted online news outlets, with the government ordering many to close or shift away from critical reporting.

Q Daily, a news site in Shanghai founded in 2014, was known for running feature stories on social issues, including problems facing rural migrants in big cities.

But the authorities have repeatedly shut down Q Daily over the past year, including in late May. The government has accused it of illegally “conducting original reporting” and harming public opinion.

Yang Ying, the website’s editor-in-chief, said the interference was crippling Q Daily’s business. The site has tried to abide by the government’s strict controls by avoiding sensitive topics like politics and the military. But she said it was often unclear what might anger the authorities.

“There is no dignity running media here,” Ms Yang said.

Before Mr Xi took control, Chinese journalism had entered something of a golden age, with reporters publishing investigations about faulty vaccines and shoddy buildings toppled by earthquakes.

But under Mr Xi’s rule, harassment of journalists has worsened. At least 48 journalists were in prison in China as of December, more than in any other country, according to the Committee to Protect Journalists.

Experts warned that by reining in journalists, Mr Xi risked shutting off an important channel for the public to vent frustration.

“Allowing the press some freedom would serve as a safety valve,” said Yuan Zeng, a media scholar at the University of Leeds.

Despite the political climate, a small group of investigative journalists are fighting to keep their profession alive, publishing stories on social media and overseas outlets.

Mr Liu, the journalist who was detained in 2013, continues to investigate serial killers and problems in the justice system, among other topics, often under a pen name.

The best journalists in China are persistent and aware of the risks of the job, he said. “Outside of China, journalists are fired for writing false reports,” he said. “Inside China, they are fired for telling the truth.”