An undercover police officer has described how he posed as a hardened criminal for almost two years to win the trust of a suspected killer in the hope he would open up about the disappearance of his former partner. The officer, working under the pseudonym Paddy O’Hara, took the suspect, Darren Osment, on fake gun smuggling runs and once showed him a fictitious press clipping of a killing in Northern Ireland that he implied he was involved in, a jury at Bristol crown court heard. Osment told O’Hara that he trusted him “100%” and towards the end of the 20-month undercover operation allegedly admitted to the officer that he had used the “knife skills” he had as a chef to cut the body of his ex, Claire Holland, and suggested her remains ended up in the Severn estuary, the court was told. Giving evidence from behind a screen, the officer said he spent many hours with Osment and claimed he was sometimes torn between the need to protect the public from the “aggressive” suspect when he seemed about to attack an innocent person during a night out and the imperative not to blow his cover. He also said he had driven Osment when he knew he was meeting customers to sell cannabis. The operation was launched in September 2020 – eight years after Holland went missing after leaving a pub in Bristol when she was 32. Neither she nor her body have been found. O’Hara said he moved into a flat in Patchway, near Bristol, about 300 metres from Osment’s home and their first meeting was in a shopping precinct, where he struck up a conversation with the defendant and offered him casual work. It quickly became a “personal relationship”. The pair would watch sport on the television together and play pool and snooker for up to 10 hours a day. Every bit of conversation was recorded, O’Hara said. “He said he trusted me 100%,” the officer claimed. “If he married, I would be his best man.” The police designed pieces of “theatre” to convince Osment that O’Hara was a criminal. On two occasions O’Hara and Osment drove to Llandudno in north Wales to pick up firearms. On the second journey home, Osment told him: “If we get arrested I will take the blame for having the firearm.” O’Hara said Osment was often very aggressive and he had to strike a delicate balance between protecting people from Osment and not blowing his cover. “I’m in a difficult position. I don’t want to step out of my role.” But he described once having to stop Osment attacking students with a cosh fashioned out of pool balls and a sock. Another undercover officer – Mike – posed as a criminal contact of O’Hara’s while a third – Neil – was presented as a “fixer” of problems. O’Hara got Osment to help him hide £5,000 in cash and silver medallions and to act as a lookout. On one occasion, O’Hara told Osment he felt he was being secretive and showed him a fake newspaper clipping relating to a killing in Belfast in 1985 that the officer implied he was involved in. Osment began to open up to O’Hara, it is claimed. He allegedly said he had done “horrible fucking shit” and hinted her body had ended up in the Severn estuary. In June 2022 he allegedly admitted he had used his “knife skills” on her. Osment, 41, from south Gloucestershire, denies murder. The trial continues.