A former senior Chinese Communist Party official, who continuously called for political reform, has died. Bao Tong was 90 years old.

Bao was a top aide to the late Party General Secretary Zhao Ziyang, who was purged for sympathizing with the Tiananmen student-led pro-democracy protests in 1989. Bao played a key role in Zhao's political reforms.

Bao was sentenced to seven years in prison on charges that included leaking state secrets.

He remained under strict surveillance after his release, but continued to demand through Hong Kong and foreign media that the Chinese government disclose the truth about the Tiananmen incident.

Bao's remarks were not widely reported in China, where media is tightly controlled, but people seeking freedom of speech and democracy looked to him for moral support.

Family members say Bao died on Wednesday at a hospital in Beijing, where he had been receiving treatment since early this year.