Four women were allegedly confined and raped at a house in Rampur area of Feni town for around six months.
They were also tortured with burning cigarettes and electric shocks, police quoted the victims as saying.
They are aged between 19 and 26.
House owner Kawsar Bin Kashem, 33, took the four, two from Bhola and the rest from the capital, there on different dates, promising to marry or give them job, said Abul Kalam Azad, officer-in-charge of Feni Sadar Model Police Station, quoting the victims.
The women were produced before a Feni court following medical tests. The court freed them, police said.
The incident came to light on Monday, just days into the gang rape of a mother of four in Noakhali's Subarnachar early December 31 and the killing of two children in the capital's Demra following attempted rape on Monday.
According to a report of rights body, Ain o Salish Kendra, 732 women and children were raped from January 1 to December 31 last year. Of them, 203 women and children were gang-raped.
The report, revealed yesterday, also said 63 were killed after rape, while three were killed after rape attempts.
Acting on information, Feni police rescued the four from the Rampur house on Monday afternoon.
Police also recovered 53 yaba tablets and equipment used in taking drugs. The house owner and his accomplices fled.
The next day, one of the victims filed a case with Feni Sadar Model Police Station against Kawsar and some unknown people under the women and children repression prevention act.
Police also lodged a case with the police station under the narcotics control act.
Police arrested three suspects -- Md Omayer, Ariful Islam alias Arman and Md Chhoton -- in this connection.
Omayer, who along with Arman was held on Wednesday, was produced before a Feni court with 10 days' remand appeal.
The court granted three days' remand for Omayer, said OC Azad.
Chhoton was arrested yesterday.
Quoting the victims and the case statement, police said after the four women were brought to the Rampur house, Kawsar and his accomplices confined and raped them.
If the women refused to do so, they were tortured and often threatened with death.
Police said Kawsar sometimes brought unknown people to the house and they also raped the four. The victims believe that Kawsar took money from the people.
Abu Taher, resident medical officer at Feni Sadar Hospital, said police took the four to the hospital for medical tests. The tests had been done and those were sent to Chittagong Medical College Hospital for results, he said.
“We have got the names of 12 to 13 perpetrators. Drives are on to arrest them,” said OC Azad.
Shahidul Islam, inspector (investigation) of Sadar Model Police Station, said the victims gave their statements at Feni Judicial Magistrate's Court under section 22.
Our Feni correspondent contributed to this report.