FORT WORTH (CBSDFW.COM) — Fiji’s Ministry of Health and Medical Services officially ruled out infectious disease as a cause of death for a Fort Worth couple who mysteriously died after visiting the island in May.

After an extensive investigation, the Fijian government has informed the victims, David and Michelle Paul’s, family of their findings.

David and Michelle Paul (credit: Marc Calanog)

“Investigations by the Ministry and other partners, which included post mortem examination, laboratory investigations to exclude a wide range of viral and bacterial causes, toxicology and microscopic examination of tissues, have identified no infectious causative agent,” The Ministry of Health and Medical Services wrote in a statement.

Given these findings, Fiji’s health officials say there is no risk to the public and the five staffers placed under precautionary observation have all returned to work.

The cause of the couple’s death still remains a mystery and the couple’s remains will stay in Fiji pending the Centers of Disease Control’s investigation.