A Western Australian autism support organisation has raised concerns that families who challenge reductions to their National Disability Insurance Scheme (NDIS) funding are allegedly being reported to child protection authorities.

The South West Autism Network has told a parliamentary review of the NDIS that it has documented more than 20 cases involving unexpected visits from child protection officers following disability support assessments.

The organisation's chief executive, Nick Avery, claimed that some families had received unannounced visits after questioning decisions to reduce support for their children or requesting additional assistance.

Avery alleged that NDIS staff were using the possibility of child protection referrals to discourage parents from challenging funding decisions.

The organisation told the parliamentary review that similar concerns had been reported across Australia, suggesting the alleged practice was not confined to Western Australia.

However, the National Disability Insurance Agency, which administers the NDIS, has denied the allegations.

The claims have been raised as part of a parliamentary examination of the disability support system. The reported incidents remain allegations, with no independent findings confirming that referrals were made in retaliation for complaints.