A 45-year-old Australian accused of murdering a teenage girl in Thailand and stuffing her naked body in a suitcase says he was forced to kill her in self-defense. Ballarat-born Simon Peter Carman pleaded not guilty on Friday to a string of charges, including murder, after the body of 17-year-old Tunchanok Donhomla was found crammed inside black luggage in the tourist enclave of Pattaya in June. Carman picked up the teen for sex, strangled her in his Pattaya apartment and then went about his day as if nothing had happened, all while texting another sex worker, prosecutors said. Tunchanok Donhomla, 17, was found dead in Pattaya, Thailand, in June. Donhomla was allegedly kidnapped for sex before her death. The middle-aged Australian denied the charges, which include concealing and moving a body, and abducting a minor for indecent purposes, the Pattaya Provincial Court said in a news release. He claims he acted in self-defense because she pulled a knife on him and he didn’t know the girl’s real age. very sad, upset; “Myself,” he said in the strange message. But police allege Carman had hidden Donhomla’s body inside his bathroom for 18 hours while he spent the day shopping, eating and doing laundry. They found the suitcase containing Donhomla’s body lying waist-deep in grass near a train track a short distance from the beach, two days after Carman allegedly strangled her. Around the same time, police officers caught Carman in Bangkok as he tried to leave the country. In a chilling twist, a sex worker claimed she was messaging Carman while Donhomla’s body was hidden in her apartment. Australian Simon Peter Carman (fourth from left) is arrested in late June at Suvarnabhumi International Airport in Samut, Thailand, via AP Carman walks with Tunchanok Donhomla, 17, before his murder via REUTERS. “I’m so tired,” Carman wrote to her, according to 7News. “I’m going swimming today.” The court deemed Carman a flight risk and denied him bail, leaving him to await his fate in a jail cell. Sources have claimed that Carman “regularly” brought Thai women to his apartment, occasionally asking them to “clean his room.” “[Tunchanok] “She was the youngest, but they were all young,” a source told the Daily Telegraph. Others in the apartment block claimed that young women visited the apartment at least once a month and that Carman was “respectful” toward them. The beach in Phuket, Thailand is similar to one of the expat enclaves in Pattaya. Maksim Konstantinov/SOPA Images/Shutterstock A forensic glove next to the packaging of cotton swabs lies in a grassy area around where the teenager’s body was found. AFP via Getty Images Donhomla’s heartbroken family does not believe Carman’s claims of self-defence and is calling for the former truck driver and mechanic to be “executed”. “I told the police I want him executed. As a mother, I don’t know what else to say. I just want him executed,” said Donhomla’s stepmother, Oradee Bussarakum. “I asked the police if I could hit him, if I could hit him,” he said. “Please leave me. The police told me not to do it, that I would face all the consequences anyway.” With cables from the Post.