On 12 February 2007, Tza Yap Shum, a Chinese national, and owner of 90% of a fish flour company, TSG Peru S.A.C., filed a request with the International Centre for the Settlement of Investment Disputes (ICSID) for treaty arbitration against the Republic of Peru, pursuant to the China-Peru Bilateral Investment Treaty. ICSID is an arm of the World Bank, established pursuant to an international convention with the aim of resolving disputes between foreign investors and host states.

The present dispute arose when Peru's National Tax Administration Superintendence (SUNAT) allegedly froze some US$4 million in TSG's bank accounts, which SUNAT claimed was the tax charge owed by the company. According to public reports, Mr. Tza claims that SUNAT confiscated the company's assets while it was trying to challenge the charge within the legally prescribed time limits for doing so.

Mr. Tza claims that the confiscation paralysed the company and amounts to an expropriation of his company, for which he demands US$20 million. The case has attracted attention because it is the first time a Chinese investor has brought a claim against a state at ICSID for breach of obligations under a BIT. The case is pending and a tribunal has yet to be appointed.