A sex offender who groomed three young girls and tried to pay one of them off to stop her going to police has had his prison sentence increased. Prosecutors appealed the six-and-a-half year sentence handed to Theodore Conos, who also tried to groom police officers posing as a 14-year-old girl. Three Court of Appeal judges agreed that sentence, with a non-parole period of just over four years, was manifestly inadequate and upped it to 10 years on Wednesday. "Conos used his manipulative techniques persistently, and repeatedly, over a considerable period of time, and persuaded three separate victims to have sex with him on multiple occasions," the judges said. All three girls were just 15 when they met Conos, a student who was doing teaching placements as a music instructor in schools and a private tutor. He was aged between 25 and 27 at the time. He targeted his first victim after contacting her on KIK messenger in December 2017. They met multiple times and Conos, then 25, exchanged naked photos with the young girl. She later falsely claimed she was pregnant and he gave her $500 for an abortion before cutting contact. Conos later gave $300 to a friend of the girl's to pass onto her, in the hope she would not report him to police and that she would stop discussing their sexual encounters with others. A year later he met his second victim after conversing on Snapchat. They first met in a playground before having sex in his car. A month after that Conos started communicating over WhatsApp with a 14-year-old persona created by Victoria Police officers. Throughout 2019 Conos sent nude photos to undercover officers as well as explicit descriptions of sexual activities he wanted to carry out with the invented teen. He also discussed plans to meet up. Conos met his third victim after seeing her at a bus stop. He went several more times to the bus stop before talking to her and swapping social media details. He would refer to the girl as "my sweet child" and "my sweet young daughter" in exchanges and had sex with her on multiple occasions. He also gave her marijuana and magic mushrooms. Conos was caught after the girl wrote a letter to Conos' father and included screenshots of their online interactions and text exchanges. She asked the man for money for counselling. Conos said he targeted vulnerable girls with low self-esteem and told his psychologist there was a "power differential I liked". The judges said "callous indifference" was an apt characterisation of his conduct. Conos pleaded guilty to 11 charges including five of sexual penetration of a child under 16. He must serve at least seven years before he is eligible for parole. Australian Associated Press