The mother of Li Wenliang, the Chinese doctor who died after sounding the alarm on the spread of coronavirus, has demanded an “explanation” from authorities about why they tried to silence him, according to a report.

Li’s mother, whose name wasn’t provided in new footage, is now questioning why authorities summoned him to the police bureau to sign a letter acknowledging that he made false statements about the deadly virus, the South China Morning Post reported.

“Before the facts were set straight, he was called to the Wuhan police station in the middle of the night,” she said in a video on platform Pear Video. “We will not be OK if they do not give us an explanation.”

The 34-year-old doctor issued the first warnings about the coronavirus, only to become sick himself with the illness and die last week, hospital officials said.

His mother said she and his father would still support his decision to work to combat the infectious disease.

“We of course would let him go back to the front line, that was his wish and the family must support it, since Wuhan’s outbreak was devastating and he was a doctor,” she said in the video.