Nabin was arrested from Army Air Defence College at Golabandha in Ganjam district where he was undergoing training, as per preliminary reports.
A native of Naya Gaon in Haryana, accused Nabin was on leave from training when the gang rape took place.
Earlier, a 19-year-old girl was gang raped by key accused Pankaj, Nishu and one Manish at Naya Gaon on September 12. All the three accused along with two other persons have been arrested in connection with the gang rape case.
Further details in connection with the arrest made by Haryana Police are awaited.
The deceased was identified as R Krishna of Ranganathapuram in Tamil Nadu, said Sub-Divisional Police Officer (SDPO), Berhampur Sadar, Jayant Kumar Mohapatra.
His body was recovered after breaking the door of the room. The reason behind the suicide was yet to be ascertained, the SDPO said adding investigation is in progress.