UK Biobank disclosed that de-identified medical information of its 500,000 participants was briefly listed for sale on Alibaba's China-based website before being removed. The charity that runs the database informed the United Kingdom government of the incident on Monday.

Technology Minister Ian Murray said information of all members of the UK Biobank database was found listed for sale on Alibaba. The data did not include names, addresses, contact details or telephone numbers, but could include gender, age, month and year of birth, socioeconomic status, lifestyle habits, and measures from biological samples. The data involved had been made available to researchers at three institutions, and the government was informed that no purchases were made from the three listings.

Alibaba removed the data from its website following support from the UK and Chinese governments. UK Biobank said it was investigating the incident and thanked the UK and Chinese governments and Alibaba for their support and cooperation.

"We understand that the existence of these listings, even temporarily, will be concerning to you," Chief Executive Professor Sir Rory Collins said. "We want to reassure you that all the data are de-identified; they do not contain any personally identifying information (such as names, addresses, dates of birth, and NHS numbers)."

Collins said the appearance of the listings constituted a clear breach of the contract signed by the academic institutions involved. "They, along with the individuals involved, have had their access suspended," he said.

UK Biobank temporarily suspended access to its research platform, imposed a strict limit on the size of files that can be exported, and said it would monitor file exports daily for suspicious behaviour. The organisation will also conduct a comprehensive and forensic board-led investigation.

Chief Scientist Prof Naomi Allen attributed the incident to the researchers who obtained the data. "Ultimately it's the fault of these rogue researchers," she said. "They are giving the global scientific community a bad name."

Murray said the data placement on the internet did not occur through a leak or cyber-attack. "This was a legitimate download by a legitimately accredited organisation," he said. He added that thousands of Chinese researchers have worked with UK Biobank since 2012 safely and securely.

UK Biobank has collected whole body scans, DNA sequences and medical records from hundreds of thousands of volunteers for over two decades. Participants were aged from 40 to 69 when they were recruited between 2006 and 2010, and the project has led to more than 18,000 scientific publications.