The European Medicines Agency (EMA) said on Friday that a second Chinese contract manufacturer, Zhejiang Tianyu, had produced a common blood pressure and heart drug with an impurity that could cause cancer.


The alarm over the valsartan drug was first raised in July, prompting a global recall of affected pills. The EMA initially said the problem likely dated back to changes in manufacturing processes at Zhejiang Huahai Pharmaceutical in 2012.


But N-nitrosodimethylamine, a probable human carcinogen, was also found in batches of valsartan made by Zhejiang Tianyu, although at much lower levels than in the case of Zhejiang Huahai, the EMA said in a statement.


“EMA is working closely with international partners to review the impact of the NDMA detected in valsartan from Zhejiang Tianyu and will communicate as soon as additional information becomes available,” the regulator said.


The EMA has said there could be one extra case of cancer for every 5,000 patients that have taken valsartan made by Zhejiang Huahai, based on patients taking the highest valsartan dose every day for seven years.