Cape Town - It’s a piece of evidence that is of utmost importance, says forensic expert Dr David Klatzow.

Even though there weren’t any signs of drugs, medication, poison or chemical substances in the bodies of Jacques and Sunita van Dyk, a broken bone in Sunita’s neck could be a telling piece of evidence.

“I’m more interested in the broken bone in her neck. Did she fall?” Klatzow said.

He reacted to the news that the late couple’s toxicology report, which was released to Jacques’ brother, Reghard van Dyk, did not show any signs of strange substances in their blood, Netwerk24 reports.

Reghard previously said he hopes the report sheds some light on what exactly happened to the couple on the night of their death.

He did not respond when asked for comment.

The Van Dyks were found dead in their house outside Wellington in May. Sunita’s lifeless body was discovered in a bath, filled with water, and Jacques’ dog, Skollie, was found with them in the bathroom.

They died due to smoke inhalation.

“Around 20 to 30 substances can be tested for but it depends on how sophisticated the laboratory is,” David said.

The tests would only indicate the substances in their system at the time of death and would normally test for drug abuse, carbon dioxide and carboxyl haemoglobin.

The couple’s death was traumatic for the Wellington community. Only after it was discovered that Sunita allegedly had an affair with the principal of Paarl Gymnasium Primary School that people from across the country were abuzz with speculation.

The police confirmed the toxicology report was negative and said the investigation into the couple’s death is still ongoing.