The New South Wales Government is under fire over reports a Sydney high school scanned its students' fingerprints without parental consent.

Ku-ring-gai High School, in north Sydney, reportedly scanned all of its students' fingerprints for a new attendance monitoring scheme, even after some parents asked for their children to be exempt.

The Australian newspaper reports parents who complained were told the data would only be deleted if there were still objections later.

State Opposition Leader Barry O'Farrell says the NSW Government has mismanaged the program since the beginning.

"[Premier] Morris Iemma needs to explain why this controversial scheme has never been publicly announced by his Government," he said.

"Very little happens in schools that the Department of Education doesn't oversight.

"The Department of Education claims that if parents don't want their children to participate in this high school fingerprinting scheme, those students can opt out.

"Here we have claims again that students are being forced to participate."

'Benefit of the doubt'

State Education Minister John Della Bosca says he will be speaking to the school involved before making any judgement about its actions.

Mr Della Bosca says departmental guidelines clearly state that parents must give consent before their children's fingerprints are scanned.

"Today, we'll be speaking with the school, unlike Mr O'Farrell, who's scoring cheap political points against his local school," he said.

"I think the school deserves the opportunity to explain and the parents and citizens deserve the benefit of the doubt."

He says fingerprint scanning can be a useful tool for schools to keep track of attendance if it is done properly.

"You have to understand that education for people of compulsory schooling age is compulsory and schools do have an obligation to keep an accurate roll of attendance," he said.