"Meghalaya Police have completed investigation into the case and a chargesheet has been filed today," a senior home department official told PTI.
The chargesheet, filed in the court of Additional Deputy Commissioner, Judicial, slapped charges against Ahmed under Section 14 of the Foreigners Act for entering the country without any valid documents, the official said.
The BNP spokesperson was found 'loitering aimlessly' in Golf Link area of the city after which the police picked him and charged him under the Foreigners Act on May 12.
The Institute's Medical Superintendent Dr A Phukan said the senior Bangladesh politician is undergoing orthopaedic treatment for his backache and also being treated for his chest pain.
He was admitted and released after the court hearing on May 27 before getting re-admitted again at the institute for diarrhoea and other minor health problems, the official said.