TWO teenagers were brutalised, threatened with death multiple times and attacked with knives and a hammer during a horrific 12-hour ordeal inside their Tablelands home by their iced-up guardian who had not slept in three days.

The 25-year-old heavily tattooed man was handed a nine-year jail sentence for two counts of torture and other offences in the Cairns District Court on Tuesday and ordered to serve at least 80 per cent of the sentence, such was the violence of the "sadistic" and prolonged attack.

The court heard the man, who cannot be named to protect the teens' identity, had been on a three-day drug bender in Cairns in August last year, leaving the pair at home in the small Tablelands town with no food and limited money.

The man, who was 23 at the time, was in a relationship with the 16-year-old girl, but returned home angry late in the afternoon and falsely accused her and the 15-year-old boy of engaging in sex acts while he was away.

Crown prosecutor Nicole Friedewald told the court he took them to a bedroom, locked the door, interrogated them and proceeded to assault and threaten the pair until the next morning.

Among the violence he stabbed the girl with a knife, leaving the blade embedded in her torso, knocked her unconscious with a hammer, punched her repeatedly and stabbed her in the back of the neck with a flick knife.

The boy was also repeatedly punched and ordered to kill the girl if he wanted to leave alive, walking towards her with a knife before dropping it and refusing.

Among the verbal abuse the man told them he would "send them home in a body bag", "do you want to see someone take their last breath" and "stab and shank" them.

The pair finally escaped after two youth justice workers arrived for a planned visit and became concerned.

Even after his arrest the man called his mother from jail who put the girl on the phone and told her to drop the charges.

"This was a protracted event of over 12 hours … continuing over a whole night and into the next morning," Ms Friedewald said. "(It was) not just painful, there were times when his actions were sadistic and calculated."

The court heard the man only has brief memories of the ordeal due to his drug intoxication which Judge Dean Morzone said left him in an "impaired state".

"Your threats were serious, the violence was serious and done against children," he said.

The court heard he also bit a prison officer at Cairns Hospital while being treated and refused to give police access to his phone. He will be eligible for parole in 2026.

Originally published as 'Sadistic': Teens' terrifying 12-hour torture in house of horrors