Tooba Mohammad Yehya, left, her son, Hamed Mohammad Shafia, and husband, Mohammad Shafia, are seen outside a Kingston, Ont., courthouse last week. (CBC)

The lawyer for an 18-year-old man charged with taking part in the slaying of his three sisters and his father's first wife says the Napanee, Ont., detention centre has violated a court order by placing his client in the same cell with his father.

Hamed Mohammad Shafia is facing murder charges along with his father, Mohammad Shafia, and his mother, Tooba Mohammad Yehya.

The three were charged in the deaths of Zainab Shafia, 19, Sahar Shafia, 17, and Geeti Shafia, 13, who were found dead last month along with Rona Amir Mohammed, 50, in a submerged car at a Rideau Canal lock near Kingston.

Shafia's lawyer, Jean-Claude Dubé, said Wednesday his client was put in the cell with his father after he was beaten by another inmate.

"There is a court order under which they cannot be in touch with each other, except for preparing their defence with their lawyer. So how come they've been in the same cell, I don't know. I don't know who takes the decision also, but let's say the detention centre should know the conditions from the court."

Dubé said he has been told the elder Shafia has since been transferred to the Ottawa-Carleton Detention Centre.

Dubé said he will go to Quinte Detention Centre in Napanee where he hopes to meet with his client and get more details on what happened.

The three accused, who live in the Montreal neighbourhood of St-Léonard, are being held in custody while waiting for bail hearings.

So far, Ontario's Ministry of Community Safety and Correctional Services has refused to comment on the situation at the detention centre.