43-year-old Ms Mukerjea, the prime accused in the murder of 24-year-old Sheena Bora, was rushed from the Byculla Women's Jail and admitted to the state-run JJ Hospital in Mumbai after she collapsed on Friday leading to speculation that she might have attempted suicide in a suspected drug overdose.
Principal Home Secretary (Prisons) Vijay Satbir Singh said the probe would cover all aspects, including whether the medicines or any other thing she consumed were prescribed by doctors and if there was an overdose and how it happened.
The probe will also ascertain if there was any negligence or foul play, he said.
JJ Hospital Dean Dr TP Lahane said Ms Mukerjea, the wife of media baron Peter Mukerjea, said she is in a "deep sleep" right now.
Briefing reporters on her condition, Dr Lahane said, "We cannot say that Indrani is out of danger before the next 48 hours. 72 hours are very critical out of which 24 hours have already passed. We will be able to say only after 48 hours whether her condition has improved or not."
He said "she is in a deep sleep right now but her blood pressure and pulse levels are normal. She is not on ventilator support but we are providing her with oxygen because she is not able to breathe automatically," he said.
Dr Lahane said a report on Ms Mukerjea's urine samples from Hinduja hospital laboratory confirmed that level of benzodiazepine - an anti-depressant - was found raised.
"Normally if a patient is on antidepressant drug the level of benzodiazepine in urine is 200. But the level of benzodiazepine is 2088 as per the Hinduja report. The report is positive for drug overdose. Anti-epileptic drugs has already been ruled out. The (test) has come negative. It is only the anti-depressant that has caused the thing(collapse)," Dr Lahane told PTI.
Dr Lahane also said that cholinesterase level was found to be normal which ruled out opium poisoning.
He had said yesterday that Ms Mukerjea was on epilepsy medication. "We suspect that she got her epilepsy medicine and probably consumed all of it," he added.
Jail authorities said she has been on anti-epileptic pills since September 11 after she started suffering convulsions.
Dr Lahane and Mr Singh at the same time said reports of her stomach wash were found "negative"
The JJ Hospital report said no drug trace was found in the gastric test conducted there after Ms Mukerjea was admitted in an unconscious state.
"We did not find the drug in the gastric test. If the drug must have dissolved in the body we will come to know when we get the urine and blood sample report by tomorrow evening," Dr Lahane said. Blood and urine samples were also sent to Kalina Forensic Laboratory.
Dr Nitin Chutke, Deputy Director of Government Forensic Laboratory, said, "urine, blood samples sent to us, stomach wash were all negative. There is no trace of drugs. Possible drug overdose is ruled out."
Asked if any report has emerged that she had attempted suicide in the prison yesterday where she was lodged under judicial remand, Dr Lahane said, "we cannot say anything about that for now."
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