A woman and her two-year-old daughter were found dead in their house at Sabujbagh in Dhaka yesterday morning.
The deceased were identified as Shantona Begum, 22, wife of Mamun, and her daughter Mahfuza, said Abul Kuddus Fakir, officer-in-charge of Sabujbagh Police Station.
Police primarily suspected that the mother commited suicide after killing her baby.
Shantona might have comitted suicide as her husband eloped with her younger sister two days earlier, the OC quoted locals as saying.
The couple and their daughter lived in a tin-shed house in Sabujbagh since last five years, said their neighhbour Monir Hossain.
The bodies were found hanging from the ceiling at around 7:30am yesterday, he added.
The Dhaka Medical College Hospital (DMCH) doctors declared them dead and sent the bodies to the morgue for autopsy.
Shantona's younger sister Swarna moved with them three months ago in search of a job at an RMG factory.
Mamun and the girl left the house on Sunday without informing anyone, Monir said, adding that Shantona was upset after her husband and sister eloped.
Meanwhile, the duo was arrested from the capital's Uttar Khan at 6:00pm, said Abul Kuddus Fakir, officer-in-charge of Sabujbagh Police Station.
“The duo has been taken into custody and are being interrogated” the OC said.