The dramatic three-day rescue of a youth soccer team from a flooded cave in Thailand last year was so complicated that the boys needed to be heavily sedated with their arms handcuffed behind their backs, according to a new book.

The 12 Wild Boars spent more than two weeks trapped in the Thailand's Tham Luang Nang Non cave complex after being flooded by annual monsoon rains. The last of the members of the cave were pulled out by July 10, drawing celebration across the world.

Thai officials had provided details of the rescue, saying how the boys would use wetsuits and flippers to swim in a buddy system with expert divers to the surface But a reporter who covered the team's ordeal says that's not exactly what happened.

THAI SOCCER TEAM GIVEN DRUGS TO MAKE THEM 'NOT STRESSED' DURING CAVE RESCUE, OFFICIALS SAY

In his new book, "The Cave," ABC Australia Southeast Asia correspondent Liam Cochran said that the boys were drugged with ketamine and handcuffed on their journey out of the cave, according to News.com.au.

“To calm nerves, the parents were told the boys were being taught how to dive and the media reported that each of them would be tethered to an air hose and then swim out with one rescue diver in front and another behind,” Cochrane writes in his book. “This was untrue."

After the rescue, Thai Prime Minister Prayuth Chan-ocha said the boys were given an anti-anxiety medication, anxiolytic, to help with their perilous removal from the cave.

But Cochrane writes the boys received far stronger drugs, and were handcuffed behind their backs to stop them from ripping off their tightly-fitted face masks if they woke up.

“Those who’d been inside the flooded tunnels knew there was no way a child who had never dived before could make it through the muddy and treacherous obstacle course," he writes. “The only hope was to sedate them, put oxygen-fed masks with silicone seals over their faces and let the expert cave divers carry them out."

THAI CAVE RESCUE TIMELINE: THE DANGEROUS RACE TO BRING TRAPPED SOCCER TEAM HOME

The first boy to be taken out, 14-year-old Note, was given a sedative to swallow then was injected with ketamine in each leg, according to Cochrane. He then was handcuffed and had cables placed around his wrists and tied behind him.

“This was to ensure that if he did wake up from his ketamine slumber, he wouldn’t try to rip off his face mask, endangering both his life and that of his rescuer," he wrote on his book.

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After going through the first flooded chamber of the cave in a harness strapped to another diver, the 14-year-old was medically checked before continuing the journey underway to the surface.

“The two biggest dangers underwater were the boy waking up and panicking, or his mask leaking and turning that plastic and silicone bubble of life over his face into a death trap,” Cochrane writes. “Preventing the mask from becoming dislodged was a constant concern.”

Divers then used similar techniques to get the remaining boys out.

THAI CAVE RESCUE ALMOST ENDED IN DISASTER, AFTER MAIN PUMP REPORTEDLY FAILED

Officials have previously disclosed the team's rescue almost ended in tragedy after a main pump malfunctioned, sending water into the caverns as the remaining rescuers were still trying to get out.

A rescue volunteer, former Thai navy SEAL Saman Kunan, died during the early stages of operation when he ran out of oxygen.

After the rescue, officials said the Tham Luang Nang Non cave complex will become a "living museum" to showcase the harrowing ordeal.

Fox News' Edmund DeMarche, Nicole Darrah, and the Associated Press contributed to this report.