A private-sector think tank that has conducted public opinion polls in Hong Kong for more than 30 years says it will suspend its research activities indefinitely.

The Hong Kong Public Opinion Research Institute is mainly led by university researchers. It has conducted opinion polls since the early 1990s, before Hong Kong's reversion to China from Britain in 1997. Its surveys have covered such issues as the performance of the Hong Kong government, freedom of speech and the press, and the human rights situation in China.

The institute announced on Thursday that it will suspend its research activities indefinitely, including its regular tracking surveys conducted since 1992.

The institute explained that it "has always been law-abiding, but in the current environment, it has to pause its promotion of scientific polling."

The institute has come under growing pressure since 2020, when the national security law for Hong Kong was put into force with the aim of cracking down on critics of the government.

In December last year, a former senior member of the institute who had moved to Britain was put on a wanted list by the Hong Kong police. He was accused of inciting secession through social media posts.

In January, the police raided the office of the institute and questioned its president.