Inappropriate touching

My son 'Andy' is 15-years-old and high-functioning autistic. Yesterday, his 5-year-old brother blurted out that his brother had touched him inappropriately. Needless to say,
I am devastated to the point where I don't even know what to do. I know I am supposed to be the strong one, but I am in a state of absolute despair.
Andy denies it, but with him being autistic, he doesn't displayed any emotion when I asked about it, or even this morning before leaving for school. Whether
guilty or not, a 'normal' person would have been livid at such an accusation, so I don't know what to believe. Is this common with autistic children?
What should I do? Please help.

[AntonReiser]

Simply treat him like you would treat any child who has misbehaved badly.
And try to cool down.

[Autist85]

It is common that they may have problems with understanding what is appropriate and inappropriate actions when it comes to sexuality. A good amount on the books about autism and sexuality has it focus on how to teach the young about moral issues; like what is private and not, and what is appropriate and not. Isabelle Henault writes in her book "Asperger's syndrome and sexuality": "Individuals with AS may have difficulty judging the appropriateness of expressing a sexual behaviour in a given context".

[hopeless777]

But what to do next? Should I reach out to a behavioral therapist and if so, is he liable to go to the authorities or is he bound by the doctor/client confidentiality?

[AntonReiser]

How did the situation develop? What happened the last two weeks?