Officials are investigating the death of an American couple who contracted an unidentified illness during their Fiji vacation, authorities confirmed Monday.

ABC News reports David and Michelle Paul of Fort Worth, Texas, arrived in South Pacific on May 22 and began experiencing a range of symptoms that included vomiting, diarrhea, and numb hands. The young couple was then admitted to a hospital, but succumbed to the illness within days of each other, Fiji's Ministry of Health and Medical Services said.

"CDC has received a request for assistance from the Ministry of Health in Fiji regarding the death of an American couple in Fiji of an unidentified illness," the CDC announced in a statement. "CDC is working with the government to investigate, including receiving specimens for testing in CDC laboratories. As per protocol, we will share results with the Fiji Ministry of Health when available."

Michelle's father, Mark Calanag of Las Vegas, told ABC News the couple was fine when they dropped off their 2-year-old son right before their trip. He is now calling for an independent investigation by U.S. agencies. David and Michelle's bodies remain on the island, while officials try to determine the source of their deaths.

"I gave them instruction not to do any cremation until I'm satisfied ... because I would like the whole world to know if they died of infectious diseases," Calanag told ABC News. "The CDC can confirm that and tell Americans and other people that these are the issues you're going to face if you have to travel to Fiji. Be aware [...] I assume on the death certificates the reason they died is there, but I'm not confident of getting the information only from Fiji. I'd really like to have the U.S., especially the CDC to confirm it because they are the experts." 

The outlet reports five people who came in contact with the couple in Fiji are now in the hospital for observation. These individuals—two security guards, tow medical staffers, and a police officer—have had symptoms similar to those experienced by the American couple.

The Fiji government is also working with the local police forensics department as well as the World Health Organization during the investigation. 

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