"As we were taking off, we were half expecting someone to pop up running alongside the aircraft, holding a shotgun and telling us to stop," said Karen Burke, one of the five who spent nine months in detention in the remote town of Merauke.

"But it was wheels-up and now we are home."

Ms Burke and her friend Keith Mortimer both devoured a meat pie as their first act after clearing customs at Horn Island in the Torres Strait.

"It was nice to have something other than mie goreng [fried noodles]," said Ms Burke, a hotel receptionist.

She retired to the Torres Hotel for a beer with friends, while Mr Mortimer - a retired builder - headed straight for his beloved boat, heading off by himself to contemplate how a three-day holiday turned into a nine-month legal nightmare.

The two, along with William and Vera Scott-Bloxam and Hubert Hofer, had been imprisoned, set free, and then placed under detention again for the relatively minor offence of arriving without a visa or security clearance for the politically sensitive province of Papua.

"What we did was stupid but there were a lot of mitigating circumstances. They told us to land when they knew our circumstances, and also after we had offered [mid-air] to go home," Ms Scott-Bloxam said.

"We thought they would deport us, at worst, but the whole thing just got completely out of hand. The Attorney-General took over and that was it. It was really quite scary to see judges who were just puppets for Jakarta."

The five were originally sentenced to between two and three years in prison, a stunningly stiff verdict given almost all illegal immigrants are simply deported.

"Believe me, being in jail in Indonesia is not like an Australian jail," Ms Scott-Bloxam said. The cells would flood during heavy rains and all five lost a great deal of weight and developed a variety of ailments.