A doctor in Wuhan, China, who was silenced by local authorities after he became one of first to warn people about a mysterious infection taking hold in the city -the coronavirus -has now died after contracting the virus himself.

Ophthalmologist Dr. Li Wenliang's condition became critical and he died early Friday morning local time, according to a post from the Wuhan Central Hospital on the Chinese social media service Weibo.

"We deeply regret and mourn this," hospital staff added.

His cause of death was coronavirus, the staff said, something he had contracted while treating other patients.

In late December, Li began warning medical friends online of a SARS-like virus that was infecting people in Wuhan and had quarantined a patient in his hospital.

Hours later, he was grilled by local authorities who asked him how he had obtained the information and why he had shared it. Within days, police also spoke with him.

"I felt a little afraid — afraid I would be detained, afraid my family would worry," he told CNN earlier this week via text message from his hospital bed.

Police made him and several other medical workers sign a document promising not to spread further "false" information online.

But within weeks, the outbreak worsened in the city and spread to other parts of the country, resulting in hundreds of deaths across China and a global health emergency.

“If the officials had disclosed information about the epidemic earlier,” Li told the New York Times last week, “I think it would have been a lot better. There should be more openness and transparency.”

Li was hospitalized in mid-January after showing fever symptoms, according to English-language Chinese state media outlet Global Times.

On Weibo, Li was being praised as a hero for speaking out about the virus.

China's top court even wrote a post last week that criticized local authorities for working to suppress early information from Li and others.

"It might have been a better way to prevent and control the new coronavirus today if the public had believed the ‘rumor’ then and started to wear masks and carry out sanitary measures and avoid the wild animal market [where the virus is believed to have begun],” the commentary said.

Upon Li's death, Dr. Mike Ryan, the executive director of the World Health Organization health emergencies program, paid tribute to him. "We are deeply saddened by the passing of Dr. Li Wenliang," Ryan told reporters. "We all need to celebrate the work he did on [the coronavirus]."

According to the New York Times, Li was 34 and leaves behind a child and his pregnant wife.