I have been informed that under Thai law , a shareholder in a Thai company is not entitled to see the annual return / balance sheet. Is this correct? When I say entitled, I mean an application to the company for a copy.

Are you talking about before they release it to the public?

My understanding is that all Thai limited companies are required to with an annual general meeting of shareholders and that accounts most be tabled at that meeting

You're entitled to see the annual report and accounts. As jbaldwin says voting and approval of these should be an agenda item at the Annual General Meeting.

Cheers

Fletch