Gardaí investigating the killing by stabbing of a three-year-old boy in south Dublin have arrested a woman for questioning.

The woman, who is in her 40s, was detained in south Dublin on Wednesday morning. She is the chief suspect in the case and the Garda is not looking for anyone else at this time.

The Garda Síochána has said it is conducting a “homicide” inquiry – an unlawful killing that may or may not prove to be murder.

Detectives detained the woman under Section 4 of the Criminal Justice Act, allowing for her detention for 24 hours without charge. When the period of detention expires she must be charged with an offence and brought before the courts or released without charge.

She was being questioned at Crumlin Garda station in the investigation into the killing of Omar Omran.

The boy, who had a condition that sources believed was autism, was found dead in the bedroom of the apartment where he lived with his mother in the Riverside development, Poddle Park, Kimmage.

His mother, Maha Al-Adheem, was also found with stab wounds in the apartment by the emergency services who responded to her 999 call. A Dublin Fire Brigade ambulance was dispatched to the apartment because the incident was a reported as a medical, rather than criminal, emergency.

Ms Al-Adheem, a doctor from Iraq who has lived in Ireland for almost six years, was unable to open the door at the time and it was forced open.

When paramedics gained access to the apartment they found the boy, unconscious, in a bedroom with multiple stab wounds and his mother also with stab wounds.

Efforts were made to revive Omar, but he had been stabbed multiple times some time on late Monday afternoon, several hours before the emergency call was made between 6.30pm and 7pm.

His mother had stab wounds to her torso and was taken by ambulance to St James’ Hospital. She has since undergone a surgical procedure and is expected to make a full physical recovery.

Her mental state has also been assessed by medical staff and the Garda permitted to speak to her about the events that resulted in herself and her son suffering stab wounds.

The apartment where the stabbing occurred was sealed off overnight on Monday into Tuesday morning and has undergone an examination by the Garda Technical Bureau.

A number of knives have been taken from the scene for examination.

Gardaí have also conducted house-to-house inquiries in the block, with neighbours reporting they would often see mother and child together. Ms Al-Adheem was separated from her husband, who is also from the Middle East.

He still lives in Ireland and is said to have played an active part in the boy’s upbringing.

The woman being questioned about the Omar’s death was expected to remain in Garda custody for the full 24-hour period of detention permitted.