A B.C. man accused of stabbing his two daughters to death is offering an alternate explanation for the killings, alleging that someone else came into his home and attacked his family.

Andrew Berry took the stand in B.C. Supreme Court on Wednesday morning, telling the court he did not kill his daughters or attempt suicide on Christmas Day 2017.

He has pleaded not guilty to two counts of second-degree murder in the deaths of six-year-old Chloe and four-year-old Aubrey.

The two little girls were found dead in his Oak Bay apartment. Berry was lying naked and seriously injured in his bathtub.

During his opening remarks on Wednesday morning, Berry's lawyer Kevin McCullough sketched the outline of his defence, drawing a link between the stabbings and the substantial debt Berry owed to a loan shark named Paul.

McCullough said Berry will testify, that on Christmas morning, he played with his daughters in the snow for hours. He alleges that when they returned to the apartment in the afternoon, Berry was attacked in the bathroom and knocked unconscious. McCullough said that when Berry woke up he found the girls dead in their bedrooms.

The trial has already heard how a suicide note was discovered in Berry's apartment after the girls were killed, but McCullough said that note was a month old. He claimed it was written when Berry hit "rock bottom" at the end of November, after he realized he wouldn't be able to pay his debt.

The bodies of six-year-old Chloe Berry, left, and her four-year-old sister, Aubrey, were found in their father's Oak Bay, B.C., apartment on Christmas Day 2017. (Submitted)

Berry later told the court that he'd tried to hang himself on Nov. 28, 2017. Both he and McCullough choked up as he recounted the memory.

Court has heard that the note, addressed to Berry's sister, laid out a long list of Berry's frustrations with his mother and Sarah Cotton, the girls' mother.

"Betrayed, bullied, and miscast I set out to leave with the kids. I love you and [your children] but I felt it better for myself and kids to escape," one line of the note read.

Owed $25,000

Berry wore a light blue plaid shirt and navy blue slacks as he addressed the jury. He spoke in a soft voice, and occasionally had to be asked to speak up.

He testified that he owed $25,000 in gambling debt to someone named Paul at the time of the killings. Though Berry said he'd gambled alongside Paul at Metro Vancouver casinos for about 20 years, he didn't know his last name or where he lived — just that he was a tall, Chinese man in his 50s.

He alleged that at one point, a rock was thrown through the window of his apartment, and Paul called soon after to ask if Berry had received the "present."

Berry said that, as part of his arrangement to pay back Paul's money, he agreed to keep a series of packages in his apartment, which he assumed to be drugs. In the weeks before the girls were killed, he said he'd given his spare keys to two of Paul's associates, whom he described as young Chinese men.

Berry told the court that after he was arrested and charged with murder, he asked to be placed in protective custody.

"I was fearful they might try it again," he said, later clarifying that he was specifically afraid of Paul.

Berry is questioned by his lawyer, Kevin McCullough. He also claims he owed money to a loan shark known only as Paul. (Jane Wolsak)

Tense proceedings

Wednesday marks the first day for the defence's case. Crown prosecutors finished presenting their evidence on Friday, more than four months after the trial began.

The proceedings have been tense at times, interrupted by frequent objections from both the Crown and defence. McCullough has suggested that some Crown witnesses are manipulating their evidence for the jury's benefit.

As Berry began his testimony, he described a close, loving relationship with his daughters. Chloe was the talkative one who'd approach strangers on the street, while Aubrey was shy and reserved.

At times, he choked up as he recounted his memories, but quickly collected himself each time.

Before the trial broke for lunch, he briefly touched on the difficulties in his relationship with Cotton. He talked about how he'd lost access to the girls in 2013 after entering a peace bond following his arrest on domestic assault allegations, and then again following an allegation of sexual abuse.

But Berry claimed he was never angry with Cotton after those incidents, telling the court "It just wouldn't have served any constructive purpose."

He said he and Cotton never let the tension between them filter down to their children.

Berry's testimony continues on Thursday.