Kathreen Ricketson and Robert Shugg.

Kathreen Ricketson and Robert Shugg.

There will be no inquest into the death of a couple who died while snorkelling near Western Australia's Ningaloo Reef, with a coroner saying there is no evidence they may have suffered deadly jellyfish stings.

Canberra woman Kathreen Ricketson, 41, washed up at Elle's Beach south of Coral Bay on May 15 as her two children, a 13-year-old girl and 10-year-old boy, looked on.

After the boy saw Ms Ricketson and partner Rob Shugg face down in the water, he raised the alarm. Attempts to resuscitate her failed and Mr Shugg disappeared before he could be recovered, sparking a massive air, sea and land search. The 48-year-old washed up on the same beach nine days later.

Kathreen Ricketson was writing a book about a year-long road trip across Australia.

Kathreen Ricketson was writing a book about a year-long road trip across Australia.

The coroner's registrar at Carnarvon Magistrates Court has since advised that a formal finding was handed down after an inquiry.

''The coroner has made findings that both deceased died by way of drowning,'' the registrar wrote. ''The coroner determined that death occurred by way of accident.

''There is no evidence to confirm or deny the involvement of irukandji.''

Robert Shugg, still missing off the WA Coast (Photo from Instagram).

Robert Shugg.

Media reports speculated the deaths could have been linked to a spate of irukandji jellyfish stings.

AAP