However, in a new study, a working committee of medical experts at Australia‘s National Health and Medical Research Council (NHMRC) has claimed that homeopathic medicines are only as effective as placebos at treating illness. Their research, involving the analysis of numerous reports from homeopathy interest groups and the public, concluded that there is no reliable evidence that homeopathy works.

Question 45. What does the word " their" in paragraph 2 refer to?