London - China has failed to improve human rights in the run up to the Beijing Olympics and risks "permanently sullying" the legacy of the Games, human rights group Amnesty International has said.

A highly-critical report by Amnesty, entitled The Olympics Countdown: Broken Promises, accused the Chinese authorities of giving empty reassurances over human rights and of having "betrayed Olympic values."

"The Chinese authorities have broken the promises they made when they were granted the Olympics seven years ago," campaigns director Tim Hancock said in the report published Tuesday.

"They told the world that the Olympics would help bring human rights to China, but the government continues to persecute and punish those who speak out for human rights ahead of the Games," he said.

"The Olympic values have been betrayed by the Chinese government."

Amnesty called on the Chinese authorities to release all imprisoned peaceful activists, allow foreign and national journalists to report freely, and make further progress towards the elimination of the death penalty.

Otherwise China would risk "permanently sullying the legacy of the Olympics," said Amnesty.

World leaders attending the Games should send an unequivocal message that they support human rights for the Chinese people, said Hancock.

"They should highlight the cases of individual Chinese human rights activists who have been silenced by the authorities. A failure to do so will give the impression that it is acceptable for a government to host the Olympic Games in an atmosphere of repression and persecution."

Amnesty also launched an online animation to highlight the plight of human rights activists in China which depicts an animated campaigner being shot by a Chinese official. (dpa)