A South Australian hobby farmer will spend at least 12-and-a-half years behind bars for holding a European backpacker captive in his pig shed and raping her.

Key points: Gene Charles Bristow lured his victim by responding to an ad on Gumtree

Gene Charles Bristow lured his victim by responding to an ad on Gumtree The 24-year-old feared being shot if she tried to leave

The 24-year-old feared being shot if she tried to leave Bristow kept the backpacker's presence hidden from his wife and son

District Court Judge Geraldine Davison on Tuesday sentenced Gene Charles Bristow, 54, to 18 years in jail with a non-parole period of 12 years and six months for his crimes.

In March a jury took three hours to find Bristow guilty of aggravated kidnapping, rape and indecent assault.

The court previously heard he held the 24-year-old female backpacker captive in a dirty old pig shed on his farm at Meningie, about 140 kilometres south-east of Adelaide, for two days in February 2017.

Bristow lured the backpacker to his 40-hectare property by responding to an advertisement she posted on the website Gumtree looking for farm work.

The court heard Bristow does not accept the verdicts of the jury and for that reason, Judge Davison said it was unlikely he would be able to rehabilitate in any way.

"You have changed the course of this young woman's life," Judge Davison told Bristow during Tuesday's sentencing.

"You remain a significant danger to society as it is plain from your behaviour pre- and post- this offending that you were prepared to plan and execute your offending and then try to cover it up in hope that authorities wouldn't catch up with you.

"In an attempt to justify your own actions you have created an entirely false version of events.

"You have … sought to blame others for your behaviour in an attempt to justify your actions."

'Adventurous woman' became 'powerless and miserable'

While giving evidence, Bristow admitted to using a fake name while communicating with the backpacker online and said he lied about the farm's location, telling her it was in Lameroo — about 150 kilometres east of Meningie.

Chains used to shackle the backpacker found at the bottom of a well. ( District Court )

He also falsely told her the farm was one of several in South Australia owned by a company called "Genesis Inc", and that there was a vacancy for a farmhand because a French girl had just left.

Bristow made the drive back to the property take twice as long and took two ferries to give the young backpacker a false impression about the farm's remoteness.

He also wanted to avoid driving through the Meningie town centre and being spotted by locals.

"She felt powerless and miserable and said it was terrifying," Judge Davison said.

"She had, prior to your offending, been an outgoing, adventurous woman who had travelled the world."

Judge Davison said Bristow had likely lost his marriage over his offending and had become estranged from his children including his son who gave evidence against him.

He is also at risk of being deported back to the United Kingdom at the end of his sentence.

Bristow stood in the dock wearing a grey prison tracksuit and showed no emotion as the sentence was handed down.

Victim feared being shot if she fled

Once Bristow led the backpacker into the pig shed, which was out of sight from his family home, he pressed a replica gun against her shoulder and threatened to shoot her if she tried to leave.

Images inside the shed were earlier released by the court.

Bristow was arrested shortly after releasing the backpacker. ( ABC News )

The court heard Bristow kept the backpacker's presence on his property secret from his wife of 25 years and son, whom he lived with on the farm.

The backpacker told the court Bristow then bound her hands behind her back with cable ties, shackled her feet with chains and stripped her naked before sexually assaulting her multiple times.

"You expected her to use an animal grate as a toilet, you offered her a filthy bed with old smelly wool upon which to sleep and then bound her," Judge Davison said.

"You chained her hands and chained her legs in what must have been a terrifying experience for her.

"You took her mobile phone and disposed of it and left her alone in that shed in the middle of nowhere."

She said Bristow told her he was working as part of a sex slave ring in which men kidnapped and drugged women before shipping them to Sydney.

The woman managed to break free and used a laptop concealed in her luggage to send distress messages on Facebook, including to her family and SA Police.

When police started searching the area, Bristow unchained the backpacker and drove her back to Murray Bridge, where he checked her into a motel and left.

No remorse for terrifying ordeal

Inside the pig shed where the backpacker was forced to stay. ( District Court )

In a victim impact statement read to the court during a previous hearing, the backpacker said she felt powerless during the terrifying ordeal.

"While I was in that shed, I felt like an animal or a slave," she said.

"I was locked in chains, held against my will and had to endure things that nobody should have to endure."

The court heard Bristow rejected the jury's verdicts and maintained his innocence.

"Your offending has left her as person who feels she cannot trust others, is uncomfortable and cautious around men and is anxious and feels unsafe," Judge Davison said.

"No-one has a right to make another feel like this."