The BNP spokesperson will be produced in the court tomorrow, they said.
"We have taken into custody Ahmed in the afternoon today for completing necessary procedures as per law," East Khasi Hills district SP M Kharkrang told PTI.
He said Ahmed was discharged after his health condition was ruled to be okay by the authorities at the North Eastern Indira Gandhi Institute of Health and Medical Sciences (NEIGRIHMS) at Mawdiangdiang, about 12 km away from here.
Ahmed's counsel S P Mahanta said Ahmed was discharged today in the afternoon and currently he is under police custody.
Ahmed, who was arrested on May 12 for entering the country without valid documents, had last week moved court seeking bail to get treatment in a hospital in Singapore where he had been undergoing treatment prior to his disappearance in March.
Since his arrest, Ahmed was admitted at the high security ward of the Shillong Civil Hospital before he was shifted and admitted at the ICU of the North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences (NEIGRIHMS) last week.