In 1923–30 the League of Nations investigated the shipment of migrant labour between Liberia and the Spanish island colony of Fernando Po. Although the League concentrated its attention on Liberia, a closer examination reveals labour abuse as very much the product of conditions on Fernando Po itself. In the last quarter of the nineteenth century, black planters on the island shifted from palm oil trading to cocoa cultivation. Dependence on migrant labour and increasing competition from Europeans resulted in economic crisis in the first years of the twentieth century, with detention of labour and the nonpayment of contracts as the outcome. The eventual investigation of the trade was the product of a desire to conserve Liberian labour for use on the African mainland, rather than an attempt to relieve its abuse.