WELLINGTON, New Zealand — A New Zealand court on Tuesday blocked a murder suspect’s extradition to China, the latest repudiation of a Chinese legal system under Communist Party control.

The move came two days after hundreds of thousands of people in Hong Kong, a semiautonomous Chinese territory, marched in protest of a plan by the local government to allow extraditions to the Chinese mainland. It also followed a decision by Australia two years ago to back away from a proposed extradition treaty with China.

In a strongly worded ruling, the New Zealand court ordered the country’s government to consider human rights risks in China before deciding that the suspect, Kyung Yup Kim, should be sent there.

The case of Mr. Kim — who is Korean-born and became a legal resident of New Zealand after moving there as a teenager — poses a political quandary for the New Zealand government. It is trying to shore up its relationship with China, the country’s biggest trading partner, after hitting rocky patches over the past year.