India, Feb. 18 -- The Ringer's lactate solution suspected to have caused the death of a patient at Midnapore Medical College and Hospital in January has passed laboratory tests, chief minister Mamata Banerjee told the West Bengal legislative assembly on Tuesday.

"Samples of the saline were sent to two government-approved laboratories and it passed the tests. We have received the reports," Banerjee, who is also in charge of the health department, told the assembly during her reply to the governor's address at the inauguration of the ongoing budget session.

The criminal investigation department (CID) of West Bengal police is probing the January 10 death of Mamoni Ruidas. Three other women who gave birth at the state-run hospital in Midnap...