Torrent Pharmaceuticals Limited is the latest drug company to issue a recall of losartan potassium, a popular blood pressure drug that’s been under scrutiny for more than a year for containing probable human carcinogens.

The voluntary recall, announced by Torrent Sept. 23, affects three lots of losartan potassium tablets and two lots of losartan potassium/hydrochlorothiazide tablets. Losartan potassium is used to treat hypertension in patients with left ventricular hypertrophy or nephropathy in type 2 diabetics; potassium-hydrochlorothiazide tablets are indicated for use only in hypertensive patients with LV hypertrophy.

In its statement, Torrent said it issued the recall—the latest in a series of Torrent recalls that date back to December 2018—due to the detection of trace amounts of N-Methylnitrosobutyric acid (NMBA) in six lots of its finished product. NMBA has been found in Torrent’s drugs before, including in 60 lots of losartan potassium tablets and 54 lots of losartan potassium/hydrochlorothiazide tablets back in March, and in other manufacturers’ products, including Vivimed Life Sciences and Teva Pharmaceuticals.