A Hong Kong museum commemorating the 1989 Tiananmen Massacre, which was set to reopen later this month, has been vandalised.

Police are investigating suspected criminal damage at the June 4 Museum after a staff member discovered that the front door lock was missing on Sunday. Ten electrical sockets and fuse box switches were splashed with salt water and holes were punched into a chair.

The museum in a building in Mong Kok was set up by the Hong Kong Alliance in Support of Patriotic Democratic Movements of China and was due to reopen on April 26.

Photo: Hong Kong Alliance in Support of Patriotic Democratic Movements of China.

The massacre ended months of student-led demonstrations in China as the military was deployed to crack down on protesters in Beijing. It is estimated that hundreds, perhaps thousands, of people died.

Alliance Chair Albert Ho told reporters on Sunday that he was angered by the vandalism: “There must be a political motivation… Those who did this must be wanting to please those in power.”

“The goal is very clear – they don’t want us to open the museum as scheduled,” he added.

He said security will be improved and a surveillance camera will be installed.

The police arrived at the premises to gather evidence, including fingerprints.

Photo: Hong Kong Alliance in Support of Patriotic Democratic Movements of China.

Alliance Vice-Chair Richard Tsoi said the Alliance had not received any threatening communications beforehand. He said a volunteer had heard that a person from the mainland had tried to find out the opening date and a list of items to be displayed of the museum, but he was not certain whether the enquiry was related to the vandalism.

The Alliance opened a similar museum in Tsim Sha Tsui in 2014, but it had to close after the building’s Owners’ Corporation said the existence of the museum was a violation of the deed.

The June 4 museum this year. Photo: HKFP/Ellie Ng.

The Alliance then bought the unit in Mong Kok in an attempt to reopen the museum.

This June will mark 30 years since the crackdown.