But carer support fraud was seldom elaborate.
"It's not like they set up secret companies and all sorts of things like that ... generally speaking, they just tell lies on the forms."
Mr Landreth said those receiving carer support were first assessed as eligible for Disability Support Services.
The assessment process had not changed, but regular internal meetings with staff from the carer support payment processing centre were being held to identify improvements and how to reduce the risk of fraud.
Carer support guidelines had not been updated since 2005, and Disability Support Services would consider ways to improve them in the next two years.
Mr Landreth's branch ran a tip-off line for callers to dob in fraudsters and an audit programme that targeted "specific areas of concern" - however he could not reveal what these were.
Carer support was a good way of giving people a break from looking after disabled people - "but there is an opportunity for unscrupulous people to manipulate it to commit fraud".
Since 2008, nearly 100 people have been identified in 50 fraud investigations, totalling $1,142,870 in payments.
Seventy-seven people had been convicted, while four were found not guilty.
Seven cases involving 18 people, 394 charges and nearly $276,000 were still before the courts.
They include that against Auckland DHB health promotion adviser Sione Tupou, his wife, Meliko, and their daughter Akosita. Meliko Tupou is the full-time carer for a close family member with a disability, and daughter Akosita Tupou is the support carer.
But investigators have alleged Akosita Tupou, 32, lived in the same Meadowbank house as her mother, father and the family member they care for, in breach of the rules.
Sione Tupou is to next appear at Auckland District Court in August.
In other cases, Maungatapere couple Donna and Brian Gainford were ordered to pay back $11,851 in April following a fraud investigation.
The ministry, which received 24 carer-support claim forms each seeking reimbursement to Mrs Gainford because she had paid the carers from her own funds, got a tip-off last year that she had submitted claims in her maiden name for carers who did not exist.