The father, David Turpin, 57, had secured a transfer to the midwestern state with his employer, defence technology company Northrop Gruman, and the family had already started packing, according to multiple sources who spoke to America’s ABC News.

“There were boxes in the house consistent with moving — concentrated in hallways, entryway and bedrooms,” a source told ABC News.

Photographs taken of the three-bedroom house in Perris, about 100km southeast of Los Angeles, showed boxes and tubs piled up as if ready to be shipped.

The relocation explains why the Turpin parents said goodbye to neighbours less than 12 hours before they were arrested on Sunday, January 14.

“I saw them about 7 or 8pm on Saturday,” an unnamed neighbour told The Mirror.

“They said they needed to say ‘goodbye’ because they were getting ready to leave town.

“They didn’t say where or when they were going.

“I couldn’t believe it when I saw their pictures on the TV two nights later.”

It is not clear whether the move prompted the Turpins’ 17-year-old daughter to escape from the house and call 911 on a deactivated mobile phone. Her act of bravery led police to the house, where they found the malnourished children shackled to furniture with chains and padlocks in filthy conditions.

Mr Turpin and his wife Louise, 49, have each pleaded not guilty to 12 counts of torture, seven counts of abuse of a dependent adult, six counts of child abuse and 12 counts of false imprisonment. Mr Turpin faces an additional charge of performing a lewd act on a child.

PREACHER UNCLE WANTS TO ADOPT KIDS

Meanwhile, a battle is emerging over who will take custody of the 13 children, aged 2 to 29, once they are released from hospital.

Mr Turpin’s preacher brother, Dr Randy Turpin, reportedly wants to adopt the kids, but not before investigators speak to him about what he knew about the so-called house of horrors.

Dr Turpin Turpin has temporarily stepped down from his role as the president of Ohio’s Valor Christian College as he deals with “revelations about estranged family members”, he said in a statement.

Dr Turpin wrote a book in 2016 called 21 Days of Prayer and Fasting that promotes the spiritual benefits of depriving yourself of food and of journalling.

Authorities allege that Mr and Mrs Turpin deliberately starved their children and forced them to write in journals, hundreds of which have now been taken into evidence.

Mrs Turpin’s sister, Teresa Robinette, believes the children should be cared for by her side of the family.

“If these children go into foster care, that’s the worst case scenario,” she told Inside Edition.

“We would like to get family members of ours together to make sure that each one of these kids is placed with a blood family member.

“That way even if they are scattered they will still be with our family and they would still have a connection for life.”

Earlier this week, a judge Mr and Mrs Turpin from having any contact with their children.

OLDEST SON WAS EXCEPTIONAL STUDENT

It has also been revealed that the Turpins’ oldest son was a star student at his community college and had been named on the honour roll twice.

School officials said the son, who is in his 20s, attended Mt San Jacinto College for several years.

His mother would bring him to school and wait outside his classes for him, prosecutors said.

He did not earn a degree but was on the president’s honour roll in 2015 and 2016, college spokeswoman Karin Marriott told the Associated Press.

A transcript obtained by ABC News showed he earned A grades in many classes, including algebra, guitar, public speaking, English and composition.

Joe Chermak, who attended a musical performance at the school in May 2016, said he remembered seeing the Turpin family in the audience. The small group of family members took up almost half a row of seats and they were all wearing matching outfits — blue shirts and tan pants.

Mr Chermak thought at first that it was a group of kids from another school, but then he looked more closely and realised they all seemed very skinny.

“I noticed that one girl was skinny from her arm and pale,” he said.

— with AP