One of three members of a Muslim family in Canada, convicted of killing three teenage sisters and another woman, intends to appeal the verdict.

Prosecutors say Afghan-born immigrant Mohammad Shafia, 58; his wife Tooba Yahya, 42; and their son Hamed, 21, killed the women because they dishonored the family by defying Islamic rules on dress, dating, and socializing.

The women's bodies were found in a submerged car in a canal in Kingston, Ontario, on June 30, 2009. Prosecutors said the "accident" was staged to conceal the murders.

"It is difficult to conceive of a more heinous, more despicable, more honorless crime," Ontario Superior Court Judge Robert Maranger said after the verdict was read on Sunday.

Hamed Shafia's lawyer, Patrick McCann, said Wednesday that his client was "determined to press on and continue the fight."

McCann said the appeal was based on inadmissible hearsay evidence by key witnesses. He also suggested the trial's intense media coverage may have tainted the jury.

"Although jurors are told not to read or listen to media accounts in a case like this, it is almost inevitable that they would be aware of the coverage and may well be tainted by it," McCann told Postmedia News in an email.

"I don't know that this could be a ground of appeal, but it certainly may impact on the viability of jury trials unless the jury is sequestered," he said.

Meanwhile Canada's minister of women's affairs condemned the killings, saying, "honor-motivated violence is not culture, it is barbaric violence."