The police officers in Area C, Surulere, Lagos, have reportedly barred lawyers from gaining access to three of the protesters arrested in the area.
The protesters, calling for the reform of police, were attacked by officers, leading to the death of two of them while three were arrested.
The three protesters arrested were identified as Ademola Ojabodu aka Ojah B, Treasure and Felicia Okpara.
They were dragged on the floor and brutalised by the police before taken inside the station.
The police had hurriedly claimed that the protesters launched the initial attack on them.
Lagos Police spokesperson, Muyiwa Adejobi, claimed that the protesters "broke into the office by damaging some of the windows and broke into the cell before they were repelled".