Failure to properly diagnose children with autism can make self-harm more likely, according to experts.
It is feared that some children are suffering with mental health issues because of problems with getting them assessed for their special needs.
Welsh Conservatives have long called on the Welsh Government to give more support to the estimated 34,000 people in Wales living with autism.
They argued that ministers should bring forward specific autism legislation that already exists in England and Northern Ireland.
Preseli Pembrokeshire AM, Paul Davies, is currently bringing an Autism Bill through the Welsh Assembly, having been drawn successfully from a ballot for back-bench legislation.
Commenting on the reports, he said:
“One of the solutions to this very serious problem is the introduction of legislation to ensure that services are put on a statutory footing.
“We have a fantastic opportunity to put that right, with my back-bench Autism Bill receiving cross-party support in the Assembly.
“This Bill could ensure that there are clear pathways to diagnosis and help staff dealing with people with autism to get the training they need.”