In 2007 the ICSID concluded that MHS’s contract with Malaysia to undertake complex salvage operations considered investment even if it had not significantly contributed to Malaysia’s economic development thus failed to fall within the scope of the former interpretation of the notion of investment. This decision is significant in the sphere of international investment law as it synthesizes the former practice of the ICSID concerning the definition and conceptual elements of the notion of ’investment’. Besides, the Diana case serves for the enlargement of salvage law; however it can- not be defined as a classical source of law. It gives a new way to legal protection for salvage activity thus it contributes to the orientation in the chaotic mass of mainly customary rules related to shipwreck salvaging.