I'd love to debate you on it, but first I need to formulate my own thoughts.
Prima facie, there may be a case for there to be an absolute right not to be tortured, but depending on the moral framework - utilitarian, say - one can make a case for allowing torture in specific circumstances. Hence, not an absolute right.
Right to not be tortured is debatable
No right is absolute, and there is no single hierarchy of rights. Read Isaiah Berlin's seminal Four Essays on Liberty on why.