The family of a dead girl has spoken out against the NSW Department of Community Services (DOCS), blasting the department for forcing their child to have chemotherapy against their will.

The Daily Telegraph reported that Mark and Dianne Westley of Sydney were told their daughter Sarah, then aged 11, had incurable cancer and made the decision not to give her chemotherapy treatment.

Six years after Sarah's death the Westleys have now spoken against the DOCS intervention that they call an "incarceration”.

The couple from Gloucester said they completely researched the options available to their child and made a decision to refuse the treatment in an effort to minimize her suffering for the time she had left.

However DOCS made the decision to classify Sarah as a ward of the state and made her undergo chemotherapy.

The couple stated that the forced treatment was a complete failure. It was only after the death of Sarah that the parents got hold of the medical records and found out that Sarah already had late-stage cancer when she was first diagnosed and she was terminal when they forced her into having the painful treatments.

The Westleys relived their nightmare in the book “Sarah's Last Wish” telling how the deadly ovarian tumor was first misdiagnosed as a pregnancy when their daughter was just 11.

DOCS records showed in 12 months in the year 2008 and 2009 that caseworkers acted on 6791 cases classified as "medical treatment not provided".

A spokeswoman said the cases could be as simple as chronic head lice or an untreated broken bone to parents refusing their child a blood transfusion for personal or cultural beliefs.

In these aspects, Community Services only intervenes based on expert medical opinion that a child or young person could be seriously harmed or even die without medical treatment.