Talwar has approached the Bose mysteries not directly but through an analysis of Jawaharlal Nehru's character and behaviour combined with the available evidence in the penultimate chapter titled "What Nehru Knew".
The Talwars have been attending to patients since November 2013, when they were put behind bars.
Rajesh and Nupur Talwar are lodged in the Dasna prison in Ghaziabad since November 2013 after they were awarded life sentence in the case.
Prison officials said they had not received a copy of the High Court order and would initiate the release procedure after they get the copy.
The Allahabad High Court had yon Thursday acquitted the Talwars in the case, saying neither the circumstances nor the evidence was enough to hold them guilty.
The suspicion initially fell on 45-year-old Hemraj, who at the time was missing. But his body was recovered from the terrace of the house a day later.