BNP leader Salahuddin Ahmed could not be produced in court on Saturday by Meghalaya police in view of his 'failing health', reports bdnews24.com.
On the other hand, doctors at Shillong Civil Hospital are continuing his treatment based on his heart and kidney test reports.
They did not see an immediate possibility of Ahmed's release in the next few days.
East Khasi Hills police superintendent M Kharkrang told the news agency over phone that police cannot take Ahmed to court unless he is medically discharged by the doctors.
"Now everything depends on Ahmed's health condition. We will produce him before court as soon as doctors pronounce him fit and investigations will continue thereafter," Kharkrang said.
"It will take a while for Ahmed to get better."
Kharkhang said it would not be possible for police to find out how Ahmed landed in Shillong without taking him into custody for detailed interrogation.
On the other hand, Meghalaya DGP Rajiv Mehta said Ahmed's detention case was 'just another normal case' for the police.
The BNP leader would be produced before court like any other detainee for illegal entry into India without valid documents, he said.
Meanwhile, BNP leader Abdul Latif Jony who reached Shillong from Bangladesh on Friday said over the phone that Ahmed suffered from massive back pain due to a kidney infection and he could not sleep all night.
Jony also said Ahmed requires 'advanced treatment' which is not possible at the Shillong Civil Hospital.
The BNP leader also suffers from serious heart disease for which he used to go to Singapore for treatment, Jony told the news agency.
In such circumstances, his treatment at an advanced medical facility is of utmost importance, Jony contended.
Jony, who met Ahmed on Saturday, praised the Meghalaya police for its 'very humane handling' of the case.
"If they (Meghalaya police) had not helped him, his health would have suffered much damage."
Ahmed has expressed his gratitude to the Meghalaya government for his security and treatment through Jony.
Being asked about any move to take Ahmed back to Bangladesh, Jony said there is a possibility that Ahmed's wife Hasina Ahmed may reach Shillong tomorrow (Monday) and then hire a senior lawyer to take care of the legal process.
Meanwhile, India's Central Bureau of Investigation (CBI) is closely monitoring the developments on the Salahuddin Ahmed case.
The bureau said the department is not yet involved in the case.
"We have not taken any action. Neither have we filed any case in this (Salalhuddin Ahmed) connection…the entire episode is being handled by the Meghalaya police and the Ministry of External Affairs (MEA)," said CBI spokesperson Kanchan Prasad to the news agency.
CBI is Interpol's nodal agency in India. The Interpol's Dhaka unit has asked its Delhi unit to get Salahuddin back to Bangladesh to stand trial for cases filed against him there.