Prosecutors in Hawaii's Kauai County are looking into multiple extortion cases tied to would-be rescuers during the island's devastating floods over the weekend, CBS affiliate KGMB-TV reports. In one instance, trapped residents and visitors were told help was on the way only to be plied for money when watercraft-riding rescuers arrived.

"The boat operators would pull up on the shore and invite people onto the boat, with the idea they would carry them over to by where the St. Regis Hotel is, to get them to a place of safety," said Kauai Prosecuting Attorney Justin Kollar.

KGMB-TV reports that the rescuers then would stop their vessels about 200 yards off shore and demand payment to go any further. The station spoke with one Big Island resident who encountered her own situation during the severe weather.

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"Once we were out in the middle of the ocean, they were like, 'Did so-and-so on the beach tell you it was $200 a head on the boat?'" Liana Leaulii said.

Kauai police officials became aware of the scheme Sunday through social media posts.

"We're not going to tolerate these type of extortion (attempts) of any visitors or locals. And to the people who are doing these things, we're gonna hold them accountable," Kauai Police Department Assistant Chief Bryson Ponce said.

Officials say they have been able to track down several victims as they continue to investigate and identify suspects.

"That kind of conduct is just completely unacceptable, and there has to be swift and serious action taken against anyone who's doing anything like this," Kollar said.

Record-breaking rains fell on Kauai last weekend and the governor declared a state of emergency. The National Weather Service recorded almost 27 inches of rainfall in a 24-hour period in Hanalei.

With damaged bridges and impassable roads, the U.S. Army and the National Guard have airlifted over 300 people from the area since Monday. Many others were rescued on jet skis, reports CBS News correspondent Michelle Miller. But in the town of Hanalei on the north shore of Kauai, the U.S. Coast Guard said those rescues were impossible.

The island could see another two to three inches of rain in the next 48 hours. Because the soil is so waterlogged there, it won't take much to cause more flooding.