Four policemen were suspended on Friday after a prisoner fled from Khagrachhari hospital where he was undergoing treatment in police custody.
Superintendent of Police Md Abdul Aziz said a three-member probe body was formed and four cops were suspended over the matter.
Legal action will be taken against the cops if the investigation found them guilty, he said.
Early Thursday, Erako Chakma, an accused in a case filed over theft, fled from Khagrachhari Sadar Hospital.
He was arrested again after about 15 hours from Rubberdam area of Panchhari upazila.