China's claims to the disputed South China Sea will come under international legal scrutiny for the first time this week, but while Beijing has officially refused to take part in the case, which was filed by the Philippines at a U.N. tribunal, it has made its presence felt.

Indeed, Manila's international legal team was heading to the Permanent Court of Arbitration in The Hague to initially argue that the five-judge panel has jurisdiction to hear the case, Philippine Foreign Ministry officials said. That is because of concerns that China raised in a public position paper in December about the tribunal's jurisdiction over the matter, according to court statements.

A little-noticed decision by the tribunal's panel in April acknowledged China's objections and announced that a hearing on jurisdiction from July 7 to 13 would be held first.