Cardinal Joseph Zen, the former Bishop of Hong Kong, was speaking as the Vatican and Beijing continue diplomatic talks to solve disagreements between them on how Christianity and the Church should function in China.
The Chinese government only allows Christians to worship at state-monitored churches where clergy are selected by political officials. It also bars them from sharing their faith.
While freedom of religion is part of Chinese law, the country's Communist government is officially atheist and it is suspicious that the West is sending spies in the form of missionaries.
The Vatican does not recognise the legitimacy of those churches and clergy and wants to be able to establish its own who are free from government control and also wants the freedom to appoint its own priests and bishops.
According to The Guardian, Cardinal Zen said: "The pope used to know the persecuted Communists [in Latin America], but he may not know the Communist persecutors who have killed hundreds of thousands."
"The official bishops are not really preaching the gospel. They are preaching obedience to Communist authority."
"You cannot go into negotiations with the mentality 'we want to sign an agreement at any cost', then you are surrendering yourself, you are betraying yourself, you are betraying Jesus Christ."
"The blood of the martyrs is the seed of new Christians. If that blood is poisoned, how long will those new Christians last?"