Chris Dawson, a convicted murderer and former teacher, has had his appeal against a conviction for sexually abusing a student dismissed by the New South Wales Court of Criminal Appeal.

The court's decision, arrived at with a majority of two to one, was announced on Friday.

Dawson was found guilty in 2023 of carnal knowledge of a student under the age of 17 following a judge-alone trial held in the NSW District Court.

He was previously convicted in 2022 for the murder of his wife Lynette in 1982 and is currently serving a lengthy prison sentence for that crime.

Lynette's body has never been recovered.

In 2023, an additional year was added to Dawson's non-parole period after his conviction for unlawful sexual activity with the same pupil, leading to a maximum sentence of three years in prison.

Dawson's first eligibility for release is in 2041, when he will be 93 years old.

Dawson was employed as a sports teacher at Cromer High School starting in 1979. The court found that he had groomed and subsequently sexually abused the 16-year-old student, whose identity remains protected for legal reasons.

The majority opinion by Justices Kristina Stern and Sarah McNaughton concluded that there was sufficient evidence to dismiss Dawson's appeal.

Justice Peter Hamill dissented, advocating for the quashing of Dawson's conviction and rendering a not guilty verdict.

Despite his dissent, Hamill acknowledged that Dawson's conduct was reprehensible and that the complainant had indeed been victimized.

He stated that one of the crucial issues contested during the trial was the timing of the first instance of sexual activity, specifically whether it occurred while the complainant was still 16 years old and a student of Dawson.

Justice Stern remarked that there was a clear consensus regarding the occurrence of sexual activity when the complainant was 17 and not a student of Dawson.

She expressed confidence in the evidence presented, affirming that it sufficiently eliminated any reasonable doubt regarding Dawson’s guilt.

Justice McNaughton also noted that it was reasonable for the trial judge to conclude beyond a reasonable doubt that Dawson was guilty.

In addressing the sentencing for Lynette Dawson’s murder in 2022, NSW Supreme Court Justice Ian Harrison condemned Dawson’s actions, labeling them as 'self-indulgent brutality' during the proceedings.

The legal battle concerning his sexual abuse conviction has highlighted key issues surrounding historical cases of such nature, particularly the complexities involved in proving allegations from decades past.