Two Child, Youth and Family caregivers are facing more than 30 charges accusing them of subjecting boys in their foster care to years of abuse - including scrubbing their bodies and teeth with wire brushes.

It has also been alleged that four boys in the care of Andrew John Hemara, 53, and his wife, Jenny-Lee Hemara, 49, were chained together, made to sleep outside without blankets, and forced to run around a race track until they became sick.

The Wellsford couple and their 21-year-old daughter, Tamara Lee Hemara, are facing 38 charges of assaulting and wilfully ill-treating boys in their care.

The charges relate to four boys aged between 7 and 14, and span nearly seven years until last year.

At their home last night, Andrew Hemara said he planned to defend the charges. He declined to comment further and his wife did not come to the door.

CYF social workers made routine checks on the family, but the alleged abuse came to light only when one of the boys spoke up.

The Hemaras appeared in the North Shore District Court on May 20 and are on bail until their next appearance this month.

Andrew Hemara, a youth worker, is facing 17 charges of assault and five of wilful ill-treatment.

He allegedly ripped an earring from one boy's ear and forced his hand into a fire until it burned, and bent another boy's neck backwards over the metal pole of a bunk bed.

It is also alleged that he and his daughter forced two boys to run around a race track until they vomited.

Tamara Hemara is also charged with repeatedly punching and kicking a 14-year-old boy.

Jenny-Lee Hemara is facing 10 assault and three wilful ill-treatment charges.

She allegedly threw a metal stool at a 12-year-old boy and stabbed him in the hand with a pen.

The couple both face charges of scrubbing two boys' bodies and teeth with a wire brush, force-feeding them after shoving their faces into plates of food, chaining two boys together with a metal chain and making them sleep outside at night.

The Hemaras have been approved CYF caregivers since 2001. The children these charges relate to were placed with the Hemaras between 2004 and 2010.

CYF northern regional director Grant Bennett said that for whatever reason, these young people were not able to disclose what was happening to them despite CYF having a regular presence in the home.

"We have been working closely with the police since one of these young people made a disclosure to one of our social workers during a routine home visit.

"The minute the young person broke their silence and told our social worker, we took action."

Mr Bennett said the boys were immediately removed from the Hemaras' care and were settling in well with new caregivers.

The Hemaras' caregiver status had been revoked.

"It is immensely disappointing when people we have entrusted to care for vulnerable young people are accused of abusing them. We do not tolerate any type of physical abuse of anyone in our care and all our caregivers are fully aware of this."

Every CYF caregiver has a social worker allocated to support them, and each child in CYF care is also allocated a support person.

All caregivers must be reviewed within six months of being approved, and every 12 months after that.

Update checks are made on caregivers at least every two years. They include police and medical checks.

Social Development Minister Paula Bennett said she knew of the case.

She said a hard-line approach was taken against anyone who abused children.

"I expect any caregivers found to have abused or neglected children in their care to be prosecuted to the full extent of the law," the minister said last night.

Grant Bennett said he did not want people to think badly of other CYF caregivers because of the charges against the Hemaras.

"I would urge the public not to let their [alleged] actions cast a shadow on the remarkable efforts made every day by several thousand other caregivers who work very hard to support some of our most vulnerable young people."