From as early as the Corfu Channel case in 1949, debates have persisted over whether there is a general principle of law that could exclude illegally obtained evidence from being used in interstate proceedings. On one hand, the fullest submission of evidence is treated as a manifestation of equality in dispute resolution. The opposite approach argues that States constrain this freedom to present evidence by committing to respect international legal obligations, and thus illegally obtained evidence should become inadmissible. This paper argues that both of these polar approaches are flawed. The first approach of free reign in presenting evidence would regress the modern conception of limited sovereignty. The second approach of absolutely gatekeeping such evidence entirely dismisses a claimant State’s interest in proving the other’s illegalities. This paper makes the renewed case that rather than an absolute exclusion or inclusion, there is a requirement of ‘balancing’ competing interests in each such case. Instead of making futile attempts at reconciling municipal approaches on this point, it argues that this general principle has arisen from within the international legal system itself, drawing from recent discourse on general principles arising in this manner