The trial of a Montreal family accused of killing four other family members continues today in Kingston, with a sibling of the three girls who were found dead testifying as a defence witness.

CTV's Genevieve Beauchemin, who is at the Kingston courthouse to report on the trial, explains there's a publication ban on the identity of the sibling.

"But what I can tell you is that it was the first time, when he walked into the courtroom, that he saw Mohammad Shafia, Tooba and Hamed, and it was quite an emotional moment," she told CTV News Channel Monday morning.

The jury were asked to watched a videotaped interview that police conducted with the sibling before his parents and brother were arrested in July 2009. In the taped interview, the sibling conceded that his father had hit them a few times, but was adamant that his family couldn't have possibly committed murder.

He tells the officer there is no way his family would have murdered his sisters and his father's first wife because killing someone is "sick." Besides, he says, he is the one who argued the most with his parents.

"So why not me?" he says. "That's the second thing which gets it off my mind."

Mohammad Shafia, 59, his wife Tooba Mohammad Yahya, who turned 42 today, and their son, Hamed, 20, are each charged with four counts of first-degree murder.

They are accused of killing three of Shafia and Yahya's children -- 19-year-old Zainab, 17-year-old Sahar and 13-year-old Geeti – along with Rona Mohammad, a woman who was one of two wives in his polygamous household but whom family members intially identified as an aunt.

The bodies of the four were found in a car submerged in the locks of a canal in June of 2009. All four had drowned.

The Crown alleges that it was Shafia's anger about his oldest two daughters having boyfriends and lying to him that drove him to plot to murder them, in an effort to restore their family honour.

Shafia and his co-accused have claimed that the deaths of the four women were not a homicide and that they died in a tragic and mysterious accident.

Last week, Shafia testified he believed his daughters had shamed themselves by dating and lying to him, but he said he only learned about what he considered their scandalous conduct after their deaths. He adamantly denied killing them.

While testifying Friday, Shafia conceded that his honour was important to him but would not be enough to compel him to kill.

"But you can't regain your honour with murder --  respected lady, you must know that," he told prosecutor Laurie Lacelle .

Shafia said the Qur'an does not give permission to kill people, so he and his family would therefore not have given themselves permission to do that.

"Never, respected lady, we never allow ourselves to do that," Shafia said in Dari through a court translator.

"Tooba is a mom… How is it possible that someone will do that to his or her children?"

Lacelle suggested Shafia might do so if he thought his daughters were "whores," a term he was heard using on a wiretap recording in reference to his dead children.

In response, Shafia said that term referred only to two of his daughters. The other two victims were innocent, he said.

"Nothing can cause this, that a person…do such a terrible and heinous thing," Shafia said. "It's impossible."

It's unclear whether Tooba Yahya or Hamed Shafia will testify. Beauchemin notes that each of the accused has his or her own defence lawyers. None chose to make opening statements to delineate how they will mount their defence.

With files from The Canadian Press