The duo, Manoj and Prakash, had a purported MMS clip in their cellphones by the help of which they blackmailed the 17-year-old victim by claiming it to be hers, Shiprapath police station in-charge, Kashiram Pandey said.
They also threatened the girl's family to make the MMS public if they were not given Rs five lakh, Pandey said.
The accused's cellphones have been seized and authenticity of the MMS is being verified, police said, adding that prima facie it appears that the victim did not feature in the MMS clip.