A Chinese photographer has unveiled some 2,000 photos he took at Tiananmen Square in 1989 ahead of the 30th anniversary of the bloody crackdown in Beijing.

Jian Liu, 51, had forgotten about the photographs until last December, when he was discussing Chinese culture and history, he told Kyodo News on Thursday, speaking in Mandarin.

[Photo courtesy of Jian Liu]

When he talked about what had happened on June 4, 1989, to his 18-year-old daughter, he found that she did not know the date's historical significance, he said.

Because his daughter had been educated in China through middle school, she had not learned about the pro-democracy demonstrations following the death of Hu Yaobang, a Communist party leader who advocated for political and economic reform, and the eventual massacre that resulted when the government declared martial law to disperse the protesters.

His daughter initially did not believe such an event had occurred, said Liu. Her disbelief sparked the memory that he had taken photographs of the widespread demonstrations.

For 50 days leading up to June 4, 1989, Liu, who was a 20-year-old fashion design student at the time, observed the pro-democracy student movements and took photos, carefully choosing his subjects to avoid wasting expensive film.

Liu said he joined the movement himself because he believed it was important to document such a pivotal moment in history.

[Photo courtesy of Jian Liu]

Horrified at the deaths he witnessed on June 4, some of which he captured on film, Liu packed up his film into seven boxes and went on to pursue a career in studio photography in Beijing.

Liu has lived in the United States with his daughter since 2016 and does not have immediate plans to return to China. He now has a renewed desire to inform people around the world of the massacre and ensure it is not erased from history, he said.

After Liu's friends in Beijing spent a week searching for the 30-year-old photos, they hid the film, rolled into 60 cans at the bottom of their luggage, and delivered them to Northern California in February. After a month and a half digitizing the photos, Liu reviewed his work for the first time recently.

Many activists banned from mainland China are expected to commemorate the Tiananmen Square massacre on June 4, with demonstrations planned in San Francisco, Los Angeles and Washington.