Alberta prosecutors want the province's top court to find two parents guilty of criminal charges connected to the 2012 death of their toddler despite a judge acquitting the pair last month.

David and Collet Stephan were tried this summer on charges of failing to provide the necessaries of life to their 19-month-old son Ezekiel, who was treated with natural remedies instead of being taken to a doctor.

Now, the Crown has filed an appeal, alleging, among other grounds, that the trial judge displayed bias in his decision for comments made about the accent of an African-born doctor — who was a witness for the prosecution — which prompted a complaint to the Canadian Judicial Council.

David Stephan says he has no comment at this time but will be publishing a Facebook post later today to address the day's development.

In his decision last month, Court of Queen's Bench Justice Terry Clackson sided with the defence's medical experts in finding the boy had viral, not bacterial, meningitis and ultimately died of a lack of oxygen.

Days before the deadline, the Crown filed notice asking the Alberta Court of Appeal to either substitute a guilty verdict or order a new trial, which would be the couple's third.

The Stephans were originally found guilty by a Lethbridge jury in 2016. While the Alberta Court of Appeal upheld the conviction, the Supreme Court of Canada ordered a second trial after ruling the first judge erred in his instructions to the jury.

Judge erred, Crown alleges

Four grounds are listed in the Crown's notice of appeal, including that the judge erred "in establishing a medical standard unknown to law."

The document also suggests the judge's comments in the trial "gave rise to a reasonable apprehension of bias" and that there was further error in Clackson's assessment of credibility when he took into account "irrelevant considerations."

Clackson came under fire for comments he made about Crown witness Dr. Bamidele Adeagbo, a forensic pathologist who speaks with a thick Nigerian accent.

The judge called Adeagbo's enunciation "garbled."

A complaint filed with the Canadian Judicial Council asks for an investigation into Clackson's comments, which "could be evidence of racism." The complaint was signed by 42 doctors, lawyers and professors.

After he and his wife were found not guilty on Sept. 19, Stephan said his case "helps protect parental rights" so that parents won't be held criminally liable if they choose alternative treatments for their sick children.

He also said he would continue to fight the Alberta government for the $1.2 million he says his family has spent in legal fees.