The discovery was made during an excavation conducted jointly by Agrasar Bikrampur Foundation, a local socio-cultural organisation, and Archaeology Department of Jahangirnagar University (JU).
The Ministry of Cultural Affairs financed the project.
The excavation is the result of four years of hectic effort of the team.
Nuh-ul-Alam Lenin, Director of the Archaeological Excavation and Research in Bikrampur region, confirmed reporters from the site about over a 1,000-year-old Buddhist Vihara being spotted.
Lenin, also a Presidium member of the ruling Awami League, said it was believed the monastery had been built about 1,100 years ago.
He said over 100 precious idols and sculptures have so far been discovered from the region.
Project researcher Prof Dr Sufi Mostafizur Rahman, a teacher of the Archaeology Department at JU, said it was believed that the monastery was related to Atish Dipankar Srigyan, a child prodigy like the Lord Buddha, who was born in Bikrampur region during the regime of King Dharmapala (820 AD).