Teenagers in Child Youth and Family care were caught trying to break into cars just days after allegedly trashing a dream home in Northland.

Four boys aged 14 to 15 are accused of breaking into Neil Croft's beachside home in Ngahau Bay, 22km northeast of Whangarei, after slipping away from their caregivers.

Hikurangi Senior Constable Gavin Benney said the quartet sneaked off after being allowed to swim unsupervised while supervisors camped about 400m away.

Croft says it will cost up to $60,000 to repair his property and is accusing CYF of neglecting its duties. The youths, from Auckland, Kerikeri and Kaitaia, were under CYF care at the Otangarei Trust in Whangarei.

Police say they broke into the beachside home, blocked the toilets, ripped a $7000 TV from the wall and smashed it, punched and kicked holes in the walls, threw around flour and sugar and pulled clothes from wardrobes. They also allegedly spilt chemicals from the spa pool and ripped up a lounge suite. Someone urinated on the floor.

Two were picked up nearby by caregivers while the others returned to the campsite.

Benney said only days later three of the quartet escaped from their lodgings in the Whangarei suburb of Kamo and tried to break into vehicles. He and Senior Constable Russell Rawiri tracked them to a shed at the Kamo Bowling Club. The boys were taken into police custody and are awaiting a court appearance.

Croft had planned to move into his dream home next week. The damage was so severe he advised his wife not to look.

"[The teenagers] were meant to be under supervision, and I hold [CYF] responsible because they are paid to take care of these juveniles," he said.

CYF northern regional director Grant Bennett said the boys were "not under lock and key and they ran away from their caregivers. Their actions are obviously disappointing."