Here are the 10 latest developments in this story:
The Dean of JJ Hospital, TP Lahane, said this morning that Ms Mukerjea's condition improved overnight, but she is still not out of danger.
"Her respiration is not normal until now. Until that happens, we cannot say that she is out of danger," he said, adding that "she is in a semi-conscious state and responding to commands." He also said that it might take her three days to recover.
"We think she has consumed some tablets, we are treating her on that basis," Dr Lahane had said yesterday. Today, he said reports have ruled out opiate poisoning, but added that more test results were awaited.
According to senior police officials, Ms Mukerjea was being given two tablets - one anti-anxiety and one anti-epilepsy, every day as prescribed doctors at JJ hospital.
"The pills were prescribed on September 11 and she was supposed to take them from September 12 to 26," Inspector General (Prisons) Bipin Kumar Singh said. The probe will seek to ascertain whether she had accumulated the pills beyond the prescribed limit, he added.
Indrani's mother Durga Rani Bora died in Guwahati on Thursday evening. She was 82. No one from her family visited Ms Mukerjea at the hospital last night.
Ms Mukerjea, 43, was arrested in August and has been lodged at the Byculla jail since September 7 when she was remanded in judicial custody.
Sheena Bora, 24, was killed in 2012. The Mumbai Police has accused her mother, Indrani, step-father Sanjeev Khanna, and a driver of hatching a criminal conspiracy to murder Sheena, abducting and murdering her and disposing of her half-burnt body in a forest in Raigad, about 80 km from Mumbai.
During her lifetime, Ms Bora was presented by her mother as a younger sister.
Mr Khanna, a Kolkata businessman, and Ms Mukerjea's driver were also arrested and are lodged at the Arthur Road Prison. Ms Mukerjea's husband, Peter Mukerjea, a former CEO of Star India, has been questioned several times by the police in the case.
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