While the reboot of Minder didn't go so well... I think it's worth pointing out that Shane Richie voiced a rat Sid who enters a rich home through a toilet which has a well tamed rat as a pet, who is the lead character of the story. Sid pushed the lead character down the toilet before the lead character does into the sewer world. This movie was released before the Minder reboot, so it's may be one hint with how Shane Richie managed to get to play Arthur Daley's nephew in Minder. I think the trailer explains the entire story. It's funny because the trailer represents the whole character voiced by Shane Richie in my opinion.