A report revealing China’s effort to collect DNA from millions of men to help solve crimes is raising concerns among researchers about privacy and consent.

They say people have little control over how their information is used, and probably do not understand the implications that DNA collection has for their families.

The report estimates that those DNA profiles can be used to construct genetic links to China’s entire male population, roughly 700 million people.

The Chinese government says the database will help it to track down criminals, who are mostly male.

Scientists and human-rights activists say a genetic database containing information about people without a criminal history is unprecedented.

Researchers also fear that police might use the database to persecute people who criticize the government.

The ASPI report says that the database, which is run by China’s Ministry of Public Security, expands on previous DNA-collection efforts.

The type of genetic information that China is collecting is also controversial, because it can be used to track down family members who have not given DNA samples.

In 2019, Chinese police used the database to identify a man who had committed murder in Guangzhou in 2008.

Police used DNA from the crime scene and found a match in the database to one of the man’s relatives, who had previously been arrested for burglary.

Prinz says that such data collection is tightly regulated in most countries, but China’s database is not subject to any law.

To reveal the size of the Chinese government operation, the authors of the ASPI report compiled more than 700 Chinese-language documents that include information about genome sequencers purchased by local police, social-media accounts of local security bureaus and local media reports.

Scientists are particularly concerned about reports that blood samples are being collected without proper consent, and without informing people how those samples will be used.

They say the database could also be used for purposes other than investigating crimes, such as finding couples who had had multiple children under China’s previous one-child policy, or tracking down and punishing family members of people suspected of political crimes or criticizing the government.

And because Y-STR data can be used to construct family links, researchers say it could also reveal private information, such as paternity, in people whose information is not in the database.

In 2015, a scientist at the Ministry of Public Security wrote in the journal Forensic Science and Technology1 that there is no legal basis in China for making a database of Y-STR data.

Cost and ease of use are two reasons that China might stick with a Y-STR database, says Prinz.