The 26ft tall Pillar of Shame, which shows 50 torn and twisted bodies piled on top of each other, symbolises the lives lost during the bloody military crackdown on pro-democracy protesters in the Chinese capital on June 4, 1989.
Workers barricaded the monument late on Wednesday night, with drilling sounds and loud clanging heard coming from the boarded-up site.
The monument became an issue in October after the university demanded its removal, sparking protests from human rights activists.
It comes just days after pro-Beijing candidates won a landslide victory in the Hong Kong legislative elections. Amendments to electoral law mean that all candidates are now vetted to ensure they are loyal “patriots” to Beijing.
Authorities have largely silenced dissent following the implementation of sweeping national security laws that appeared to target the pro-democracy movement after mass protests in 2019.
Over 100 pro-democracy activists have been arrested since the introduction of the laws, which have been seen as a power grab by the Chinese Communist Party. They ban secession, subversion, terrorism and foreign collusion to intervene in the city’s affairs.
Hong Kong was previously one of the few places in China that allowed public commemoration of the Tiananmen protests, which are rarely discussed in the mainland.
"The decision on the aged statue was based on external legal advice and risk assessment for the best interest of the university," the university said in a statement on Thursday.
"The university is also very concerned about the potential safety issues resulting from the fragile statue."
The university said that it had requested for the statue to be put in storage and would continue to seek legal advice on follow-up actions.
Danish sculptor Jens Galschiøt, who created the statue, told the Associated Press: “We don’t know exactly what happened, but I fear they destroy it.
“This is my sculpture, and it is my property.”
Mr Galschiøt said that he would sue the university if necessary to protect the sculpture.