From the beginning of 2015, China imposed a total ban on the use of executed prisoners' organs for transplantation, Huang said, describing the process as "an arduous journey".
Pope Francis would like to heal a decades-old rift with China, where Catholics are divided between those loyal to him and those who belong to a government-controlled official church.
"The lack of transparency about organ sources in China is a mask of deception".
"However, China is a big country, with 1.3 billion people, so sure, definitely, there is some violation of the law".
Huang dismissed claims that organs were still being extracted from prisoners or ethnic minorities in a state-sponsored program in China.
Both Congress and the European Parliament recently condemned organ harvesting in China amid widespread concerns that tissue is sourced from detained and executed prisoners.More news: Donald Trump To Meet Canadian PM Justin Trudeau Amid Tensions Over Trade
Dr Rogers wrote again, insisting the "failure of the academy to examine the evidence that forced organ harvesting has been, and is still happening in China, amounts to a form of complicity in these crimes". It has also been reported that the execution time of prisoners is often matched with the time a recipient might need an organ.
"We, the undersigned participants of the Pontifical Academy of Sciences summit on organ trafficking, resolve to combat these crimes against humanity through comprehensive efforts that involve all stakeholders around the world", said the final statement, released to the public February 9. In a protest letter he wrote to the Vatican, he said that the Pontifical Academy of Sciences must be aware that China is even using indirect endorsements to propel the reputation of its unethical practice. "There is no new law or regulation banning the use of executed prisoner organs".
At the summit, more than 70 scientists, experts and officials from different countries and global organizations attended the discussion on organ trafficking and transplant tourism, in a bid to set up further guidelines and ethical rules in curbing illegal activities worldwide.
Beijing is working hard to stop the forced harvesting of organs but prisoners' organs are still being used in some cases, a leading Chinese transplant surgeon has told a meeting in the Vatican on organ trafficking.
In his formal address at the Vatican, Huang invoked the ancient philosopher Confucius to say that the world would see that China was "mending its ways" and stressed that the government had cracked down on offenders.