Today marks the 25 anniversary of the Tiananmen Square massacre that saw China’s People's Liberation Army gun down hundreds of civilians in a brutal crackdown on protests against government corruption, lack of transparency and freedom of speech.

The violent military response and the scale of bloodshed that ensued was followed by a further clampdown that saw the widespread arrests of protesters, the expulsion of foreign journalists and the censorship of media coverage of the event, including banning the image of a man stood in front of a column tanks, dressed in a white shirt and holding a shopping bag.

The image of Tank Man quickly became a powerful symbol of both the bloody events of 4 June 1989 and of non-violent resistance, but the identity of the ‘unknown rebel’ and his fate remains unknown. Many people in China are still unaware of his existence and only a handful of photographers were able to record the event without having to destroy their materials.

Below are some of the theories surrounding the mystery of the man captured in such an iconic picture.

He was a student

The Sunday Express went on to identify him as 19-year-old student Wang Weilin and quoted his friends as saying they feared he had been put to death. However, then General Secretary Jiang Zemin denied having nay knowledge of his arrest or even of the name.

He was pulled away to safety

Witnesses recall the man climbing up onto the first tank in the column and speaking to the person inside. Jan Wong, the former Toronto Globe and Mail Beijing correspondent, remembered seeing tanks repeatedly attempting to drive around him, before switching off their motors. The man then climbed into the tank.

She told Frontline: “After a while the young man jumps down and the tank turns on the motor and the young man blocks him again. […] I started to cry because I had seen so much shooting and so many people dying that I was sure this man would get crushed.

“But he didn't. … I think it was two people from the sidelines ran to him and grabbed him - not in a harsh way, almost in a protective way. I think that the people who took the Tank Man away were concerned people.”

But other accounts contradict this however, with many claiming he was pulled away by security agents and arrested.

He is still alive

American TV journalist Barbara Walters confronted Jiang a year after the crackdown with a photo of Tank Man and the question: “Do you have any idea what happened to this young man?” A flustered Jiang reportedly stressed that Tank Man had not been executed by the Government or run over. He highlighted the fact that the tanks in the picture were still and had not attempted to drive at him as indicative of his fate, and said: "The people in the tanks didn't want to run over the people standing in the way.

“I think ...never killed”.

Others claim police were never able to locate the man after he was pulled away from the crowd and back into the tanks. One government official was quoted as saying, "We can’t find him. We got his name from journalists. We have checked through computers but can’t find him among the dead or among those in prison."

He escaped mainland China

A report cited a professor in Hong Kong who claimed Tank Man was an archaeologist and his friend who had come from Changsha to Beijing to join the protests. The professor claimed he escaped to Taiwan and was employed by the National Palace Museum but the museum allegedly denied this report.

The Yonhap news agency in South Korea also reported that he had escaped the massacre by fleeing to Taiwan.

He was executed

Bruce Herschensohn, a former deputy special assistant to former US President Richard Nixon, told the President Club in 1999 that Tank Man was executed 14 days later.