China's most powerful leaders were asked by a retired health official to take responsibility for a huge 1990s blood-selling AIDS scandal.
Chen Bingzhong, 78, who has advanced liver cancer, wrote an open letter to Chinese President Hu Jintao pointing out that those guilty of gross negligence in the scandal in the central province of Henan have still not been punished.
In the letter, published on the website of activist group Aizhixing, the former head of the government's Institute of Health Education pinpoints "two senior officials" who have since entered China's top nine-member leadership.
Speaking to AFP by telephone on Wednesday, World AIDS Day, Chen pointed the finger at Li Keqiang -- currently China's vice-premier and widely touted to succeed Premier Wen Jiabao -- who was head of Henan from 2002 to 2004.
He also named Li Changchun, the Communist Party's propaganda chief, who served in the same position from 1992 to 1998.
Both are now part of the party's politburo standing committee, the nation's highest and most powerful decision-making body.
"They have to take responsibility. They must apologise," Chen said.
In the 1990s, entire villages in Henan were devastated by HIV/AIDS.
Many people were infected after repeatedly selling their blood to collection stations that pooled it into a tub and then injected it back into them after taking the plasma.
The blood-selling scandal was initially covered up by local officials, some of whom were actively involved. But it eventually came to light after fierce campaigning by activists -- including Aizhixing founder Wan Yanhai.
The government eventually revealed in 2001 that 30,000 to 50,000 people may have been infected with HIV through the scheme. Chen, though, said the number was closer to 100,000, adding at least 10,000 had died.
He raised the example of an HIV scandal in France in the 1980s that saw thousands transfused with blood contaminated by the virus that causes AIDS.
The incident caused huge concern and led to the prosecution of several officials including the then health minister.
"In comparison, Henan's blood scandal was much more serious than France's," Chen wrote in the letter.
"But not only were no investigations launched against those responsible for the incident, particularly the two officials who now occupy China's highest decision-making levels, but they were even entrusted with big responsibilities."