The arrestee was identified as Shahabuddin, 28, a local trader of electric machines in Gujaria Bazar and son of Md Sattar.
Sub-Inspector Md Fakhrul Hasan Faruk said Shahabuddin took the victim to an empty room of his office on Oct 1 and gave her food mixed with sedatives.
“He confined the girl there for three days and raped her,” he said.
On Oct 4, the victim was sent back to her house after she fell sick, he added.
Locals caught Shahabuddin from his office on Tuesday night when the victim disclosed the matter, the policeman said.
Her sister filed a case at Karimganj Police Station in this regard, he said.
The victim has been sent to the Sadar Hospital for medical test, the SI said.
Bangladesh has seen a surge in rape incidents in recent days. The rape of a 19-year-old girl at MC College hostel and the molestation of a women in Noakhali sparked countrywide protests with people calling for tougher punishment for rapists.
Amnesty International said the new disturbing footage demonstrates the shocking violence that Bangladeshi women are routinely being subjected to and called for a thorough and impartial investigation.
According to Ain-o-Salish Kendra (ASK), nearly 1,000 rape cases were reported, including 208 gang rapes, between January and September this year.
Also read: Why 97 pc sex offenders in Bangladesh go unpunished