A previously unseen archive of photographs from China's so-called Cultural Revolution is finally being published, 35 years after they were buried for safekeeping. BBC arts correspondent Lawrence Pollard reports.
Li Zhensheng hid his photographs for fear of recriminations
"Long live Chairman Mao", delegates to the ninth Communist Party Congress chanted in 1969.
China was then in the midst of the Cultural Revolution, a 10 year campaign of violence and chaos launched to renew the spirit of communism, and spearheaded by the feared Red Guards.
The media followed the party line. But photographer Li Zhensheng managed to gain a little freedom for himself and his camera.
"I saw that some people could take photos freely, wearing red armbands. I wasn't given one, so I formed a Red Youth fighting team," he said.
"We applied for recognition to the national headquarters of the Red Rebels in News Media, and we were given a new name - Red Colour News Soldier. Then I was free to take the pictures I wanted."
Li Zhensheng worked for a newspaper in the north-eastern province of Heilongjiang, and as well as taking positive images of the revolution, he also recorded its violence and brutality.
Top party officials were often denounced during public rallies
But fearing recriminations, he initially hid the photographs away.
Only now are the pictures coming out, in a new book which will not be available in China.
Robert Pledge of Contact Press Images, who has been closely involved in producing Li Zhensheng's book, said there were not many photographers working in Maoist China.
"Photographers were perceived as dangerous. They were intellectual, they were people who were observing what was happening, so they were denounced for the most part," Mr Pledge said.
"Most photographers were not prepared to put their lives and their careers at risk by taking pictures that were politically incorrect."
Mr Li's black and white pictures show mass rallies, ritual humiliations, beatings, executions and passionate revolutionary enthusiasm.
They are a glimpse of what the Cultural Revolution must have been like in provincial China.
Mr Li had to be careful to save his film negatives from the attentions of the Red Guards.
"It wasn't safe to have the pictures around the house, so we cut a hole in the floor and put all the damaging pictures wrapped up under the floor," he said.
"On 26 December 1968, the guards came to my house, taking everything they found, but the negatives were safe."
Mr Li said that, in his view, history should be recorded completely - with both the positive and the negative.
"Like a cake, you can't just have the icing," he said.
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"It's not only you who are shocked by the pictures. I hope if the book is published in China, my compatriots will be shocked too. I want to tell the true story of the Cultural Revolution, to serve a purpose."
Robert Pledge said that, in some ways, Mr Li was more of an artist than a photojournalist.
"He's a story teller," said Mr Pledge. "He even speaks about himself all the time. Without photography and without a camera, he might not have survived this ordeal, this period of time."
"And not only that, he did survive, but he has something to show for it, and (is) leaving something behind that is a trace of his existence," he said.