A case was filed on Sunday in connection with the double murder at a flat in the capital's Dhanmondi area.
Dilruba Khatun Ruba, daughter of Afroza Begum, an elderly woman who was brutally killed along with her domestic help last Friday, filed the case against five with Dhanmondi Police Station.
The accused are bodyguard of slain Afroza's son-in-law Atikul Hoque Bachchu, housemaid, security guard Nuruzzaman, electrician Belayet and a house worker Prince.
She said the murder was committed only a day after a new housemaid joined through one of the accused Bachchu.
"I informed the police about our suspicion. I hope they will arrest the culprits as soon as possible," she added.
Confirming the matter to The Business Standard, Subrata Boddo, sub-inspector and duty officer of Dhanmondi Police Station said, "The victim's family believe that it was a planned murder.
Abdullahil Kafi, additional deputy commissioner (Dhanmondi Zone) of Dhaka Metropolitan Police said they are trying to arrest the absconding housemaid.
"Her arrest will shed light on the murder case," he added while mentioning that the detainees gave significant information regarding the case.
The bodies of Afroza Begum, 65, and Diti 19, her domestic help, were recovered from a flat in Dhanmondi on Friday evening.
Police detained six people, including Afroza Begum's son-in-law, his bodyguard Bachchu Mia and electrician Belayet on Saturday.