 He was attached as a consular representative to a commission investigating rubber slavery by the Anglo-Peruvian Amazon Rubber Co, which had been registered in Britain in 1908 and had a British board of directors and numerous stockholders.In September 1909, a journalist named Sidney Paternoster, wrote in "Truth", a British magazine, of abuses against PAC workers and competing Colombians in the disputed region of the Peruvian Amazon.Casement travelled to the Putumayo District, where the rubber was harvested deep in the Amazon Basin, and explored the treatment of the local indigenous peoples in Peru.