The Crown suggested in court Tuesday that accused members of the Shafia family told one of their surviving children to make up a story that would back up their claims of innocence.
Married couple Mohammad Shafia and Tooba Mohammad Yahya, together with their adult son, Hamed, are accused of killing four women in their family.
Three of Shafia and Yahya's daughters -- 19-year-old Zainab, 17-year-old Sahar and 13-year-old Geeti -- were among the bodies found last year in a submerged car that was pulled out of the Rideau Canal.
The fourth victim was Rona Mohammad, the first wife of Shafia who lived alongside Yahya in a polygamous marriage.
The accused Shafia members have pleaded not guilty to the four counts of first-degree murder they each face.
On Tuesday, one of the Shafia's surviving children took the stand for the second straight day in a Kingston, Ont., courtroom.
The sibling, who cannot be named due to a publication ban, was asked about wiretap recordings that captured conversations with brother Hamed Shafia.
On the recordings, which have been played in court previously, the sibling can be heard telling Hamed Shafia that he is 100 per cent caught.
But the sibling told the court that is what the police had said in an interrogation. It was not a personal conclusion about Hamed's legal situation.
Another piece of wiretap evidence caught the siblings in a conversation that appeared to be centred on "making sure that they have the same version (of events) that they are telling police," CTV's Genevieve Beauchemin reported Tuesday.
But the sibling claimed in court that the two needed to discuss what happened to ensure they both knew the truth.
With files from The Canadian Press
