Under Australian law, only the Family Court or a guardianship tribunal can authorise the irreversible medical procedure.

But the national Disability Discrimination Commissioner, Graeme Innes, said that anecdotal evidence suggested unauthorised non-therapeutic and forced sterilisation were still common in Australia.

Mr Innes is seeking to have the practice criminalised, with penalties such as imprisonment for those flouting the law. He has written to the federal Attorney-General, Nicola Roxon, arguing that current laws had failed to protect women and girls with disability from non-therapeutic and forced sterilisation.

While exact figures in relation to non-therapeutic sterilisation within the health sector are difficult to obtain, Mr Innes said the commission had attempted to gather data on the practice but had only managed to collect figures from NSW, Tasmania, Victoria and Western Australia. This data showed permission was granted for 12 procedures over the past five years, including one in NSW for a child under 16.

Mr Innes said the commission suspected many more procedures were carried out without court consent.

''I'm seeking the criminalisation of forced sterilisations,'' Mr Innes said. ''It should be a criminal offence for any adult to be sterilised without consent and for any child at all, apart from life-saving circumstances.''

The plea comes after the Senate community affairs committee recently announced an inquiry into the involuntary or coerced sterilisation of people with disabilities.

The inquiry's architect, Queensland Liberals senator Sue Boyce, who has a daughter with Down syndrome, said menstrual management and preventing pregnancy appeared to be the major reasons families and carers sought to sterilise their disabled charges.

The Senate inquiry is receiving submissions on the issue.