Hong Kong was once home to a vibrant civil society, but scores of groups have closed since the national security law imposed by Beijing in 2020, with hundreds of pro-democracy activists arrested, jailed or in exile.

Harbour protection was one of the city's major activist causes in the decade following the former British colony's handover to China in 1997.

But the Society for Protection of the Harbour (SPH) said Friday it had ceased operations, citing a law passed this year that made it easier for the government to create new land through reclamation in Victoria Harbour.

SPH said in legal advice offered to government leaders that the amendments violate the fundamental principle of public law "by placing the roles of proposer, evaluator and ultimate decision-maker all within the power of government decision-makers".

It received no response and the bill was passed by Hong Kong's opposition-free legislature in May, it said.

Hong Kong's Secretary for Development Bernadette Linn told pro-Beijing newspaper Wen Wei Po in June the government had encountered "soft resistance" -- a vague term used by pro-Beijing politicians to crackdown on dissent -- when amending the law.

Linn pointed to a social media post produced by SPH which implied that the government's reclamation posed danger to Victoria Harbour.

SPH said on Friday it was thanks to the support of the public that Hong Kong "still enjoys a wide, deep, and beautiful Victoria Harbour".

"We sincerely hope that one day our Victoria Harbour will be declared a 'National Treasure of China' and will be protected and preserved for the benefit of the present and future generations," the group said.