it's looking very strong." Hamilton was also supportive of journalist Edward Hooper who detailed the hypothesis in his 1999 book, The River. Hamilton wrote the foreword for the book and did two expeditions to Congo between December 1999 and January 2000 to collect evidences on the OPV hypothesis. None of the over 60 urine and faecal samples collected by Hamilton contained SIV. Still, Hamilton used his prestige within the Royal Society to promote a discussion meeting about the OPV hypothesis. In this meeting, held six months after Hamilton's death, in September 2000, Hooper further expanded on his allegations, although these claims were later rebutted by some of the scientists who were present at the meeting. In 2001, Hilary Koprowski responded by making a detailed rebuttal of the points made in the book, also in a talk to the Royal Society. In 2004, the Origin of Aids, a French TV documentary strongly supportive of the OPV hypothesis, appeared on several television stations around the world. In 2003, Hooper published additional statements that he believed supported his hypothesis in an article in the London Review of Books. These included accounts of an interview with Jacques Kanyama, a virology technician at the lab in Stanleyville (the Laboratoire Médical de Stanleyville (LMS)) responsible for testing the CHAT vaccine and performing the initial set of vaccinations, who was reported to have said that batches of CHAT had been produced on site by Paul Osterrieth. In addition, Philip Elebe, a microbiology technician, was claimed to have said that tissue cultures were being produced from Lindi chimpanzees. Osterrieth has denied these claims and stated that this work would not have been possible in this laboratory, stating that: In his book, Hooper also stated that Gaston Ninane was involved in using chimpanzee cells to produce vaccine in Congo. Ninane responded to this allegation by stating that he could "categorically deny" ever having tried to make tissue cultures from chimpanzee cells. The people involved in vaccine production and distribution from America state that no vaccine was prepared locally in Congo and that only the CHAT vaccine from America was used. Barbara Cohen, the technician who was responsible for running the American laboratory that produced this vaccine stated: Scientific investigation In an August 1992 letter published in Science, Koprowski repudiated the OPV AIDS hypothesis, pointing to multiple errors of fact in its assertions. In October 1992, Science ran a story