Joseph performed basic chores on the farm and began to make progress during his stay, Mr Holloway said. But on May 11 he disappeared.
"We woke up one morning and he was gone. He left a note on the bed to say he'd got someone to pick him up down the road."
When Mr Holloway contacted the Probation Service, he was told Joseph had applied for a transfer to an Auckland address, which had been approved.
"They didn't even have the decency to tell us they'd given him permission to go."
Erni's father said the Probation Service should not have allowed him to leave the farm. "It was keeping him away from drugs. We didn't put him there for nothing - the judge didn't put him there for nothing. "I'm very disappointed in the probations people because it doesn't look like they looked into anything."
Mr Erni said he still had not heard from his son. The Holloways found a slip of paper with a phone number on it which Joseph had left at the house. When Mr Erni called this number, an Auckland woman answered and explained Joseph was coming to live with her, after she met him on the mobile dating app Tinder.
Community Corrections East Coast district manager George Henderson was unable to comment on specific individuals, but said if an offender was not subject to court imposed conditions in relation to their address, they may propose a change of address during their sentence.
"Community Corrections consider a number of things when assessing an address, for example proximity to employment and a probation office and other relevant information that might impact on the offender's ability to complete their sentence," he said.
"We work with offenders to ensure they comply with their sentence conditions. Community Corrections will work with an offender's family if appropriate, however an offender may or may not choose to include others in discussions about their sentence, including family members."
Sensible Sentencing Trust spokesman Garth McVicar described the Probation Service's handling of the matter as "a debacle, an absolute debacle".
"They never checked what [Erni] was saying was correct, they just took his word for it."