A grieving mother struggling to come to terms with the death of her young son on a school excursion in the Dandenongs is seeking damages over a suspected snake bite that possibly could have killed him.

Rowville Primary School pupil Junpeng Tan, 7, was on a day trip to the Mount Morton camp in Belgrave when he suddenly died in October 2013, court documents show.

Junpeng suffered a cardiac arrest.

The Coroner was unable to establish what caused Junping's death. The pathologist who conducted the original autopsy concluded that the likely cause of death was a suspected brown snake bite.

However a supplementary report, following further laboratory analysis, stated there was no snake venom detected in Junpeng's system.