BEIJING • China is investigating a manufacturer of medical products following reports that it sold human immunoglobulin for intravenous injection that had possibly been contaminated with HIV, though the authorities said tests found no sign of the virus.

Beijing has repeatedly vowed tighter oversight and crackdowns on firms and officials after food and drug safety scandals sparked public outrage, such as one last month over expired polio vaccines and another last year over a rabies vaccine.

Human immunoglobulin, made with human blood plasma, is used to treat a variety of conditions, but it was not clear how many people might have had injections from the suspect batch, which media said consisted of 12,226 units with a 2021 expiry date.

Tests on the suspect batch proved negative for HIV, officials said on Wednesday, following a comment by China's National Health Commission that there was a "very low" risk of HIV infection from it.

The Shanghai Medical Products Administration said in a statement that the batch, identified as number 20180610Z, was made by China Meheco Xinxing Pharma, a unit of state-controlled China Meheco Group.

Reuters could not get a comment from the manufacturer as most offices in China were closed for the week-long Chinese New Year holiday.

Domestic media outlet The China Economic Observer said the investigation began after an HIV test on a baby in south-eastern Jiangxi province initially yielded a "weak" positive result that was traced to the batch under investigation. The baby subsequently tested negative for HIV, it added.

"Shanghai authorities have run virus tests for HIV, hepatitis B and hepatitis C on the reported batch and they all show negative," the National Medical Products Administration said. It asked medical institutions to stop the use of the batch and seal remaining supplies for further investigations.

Shanghai's Medical Products Administration said it had ordered the manufacturer to stop production.

Last month, China's National Medical Products Administration asked manufacturers to add warnings against potential risks from intravenously-injected human immunoglobulin and frozen human immunoglobulin products, saying the raw materials were derived from human blood.

In 2016, the Shanghai medical products regulator warned the same company over changes to the manufacturing process for some human fibrinogen products without assessing potential risks, the regulator's website showed.

REUTERS