"We are about to detect the killer after we examined the call list of a mobile phone that we recovered from the spot," a top official of Rab-2 told The Daily Star wishing anonymity.

He however refused to divulge any more information for the sake of investigation.

Meanwhile, two domestic helps of the house Mina and Aleya, who were in the house when Sayma was slaughtered, were placed on seven-day remand yesterday.

Investigation Officer (IO) Shahjahan Ali of Newmarket Police Station made them accused in the case and produced them before the court of Chief Metropolitan Magistrate with a prayer for seven-day remand for each of them.

"We do not think that the domestic helps have any link to the killing, but it seems Aleya knows the killer," ABM Golam Kibria, officer-in-charge of Newmarket Police Station, told The Daily Star.

Police examined the entry registrar kept at the gate of Prince Tower that housed Sayma's apartment, and found that three people visited the 18-storey tower on Tuesday, the day Sayma was killed.

They said they picked up two of the three visitors yesterday and released them after questioning, as their involvement was not found in the killing.

Police suspected that the killer entered and left the tower through a narrow passage at the rare side of the high-rise tower.

A youth believed to have acquaintance with Sayma slit her throat inside her drawing room and then left the apartment.

Victim's husband Zahurul Islam, a retired engineer of PWD, filed a case without accusing anyone on the same day.

Meanwhile, all proceedings in lower courts in Dhaka yesterday remained halted till 12.00 noon in memory of the slain advocate.

A namaz-e-janaza was held on the premises of the district court.

Judges, magistrates, lawyers and general people attended the janaza.

Earlier a pale of gloom descended on the court premises when her body was taken there.