STORY: The investigation began in Australia last year after the murder of two FBI agents in Florida in 2021 who were investigating child abuse in the United States, police said.The FBI then tipped off Australian police about members of a peer-to-peer network in the country allegedly sharing child-abuse material on the dark web, AFP Commander Helen Schneider said during a news conference."The longer people like this avoid detection, the longer the cycle of abuse continues. This was a sophisticated network," Schneider said.The men, aged between 32 and 81 years old, distributed images and videos of child-abuse material, chatted on message platforms and allegedly used encryption to avoid detection.Most Australian offenders were employed in jobs that required a high degree of knowledge of internet networks. Some are accused of having produced their own child abuse material, police said.Two Australian offenders have been sentenced to jail while the others were on trial. The related FBI investigation has led to the arrest of 79 people.