A war-gamer is being tried over an accusation he perverted the course of justice by deleting data from a phone that belonged to a fellow enthusiast, whose body was found covered in blood on a Hong Kong hillside. Prosecutor Mark Wei opened his case against Jack Wong Wai-ho, 21, before a seven-member jury in the High Court after the defendant pleaded not guilty to doing an act tending and intended to pervert the course of public justice and handling stolen goods, charges stemming from May 28, 2017. Both counts relate to the death of Bosco Kwok Wai-nok, 20, who joined several war-gamers for a night hike in Tseung Kwan O the day before. His body was found covered in blood, the head wrapped in a gunny sack on Black Hill on May 29. There was no sign of his phone or the backpack he was carrying when he left home on May 27 as captured by his building’s CCTV. Instead, his iPhone was found in the home of fellow gamer, Benard Chow Ching-yin, on May 29. His backpack, headphones and some war game equipment were found in Wong’s flat two days later, according to prosecutors. An autopsy concluded Kwok had died from multiple stab wounds to the neck and injuries to the head, one to two days before his body was discovered after his family filed a missing-person report. Police discovered his phone had been factory reset, which prosecutors said had been done because the data might have contained information relevant to the investigation of his death. Upon arrest, Wong told investigators it was another gamer, Martin Yim Yu-hang, who told him to help erase the phone and “sell those things”. “I have no idea that it’s illegal to do so,” he said under caution. In later interviews, which Wei summarised, Wong further revealed he knew Yim planned to trick and harass Kwok during the hike, and Yim had given him the phone and the backpack on May 28, without telling him who they belonged to. Wong said he took the phone to Sin Tat Plaza in Mong Kok to have its data erased and returned it to Yim. The defendant also recalled a conversation with Chow, during which the latter poked him with a finger and said: “It’s 20 slashes” then “Eight strikes with a pole”. But Wei said prosecutors did not believe the defendant had told police the whole truth, arguing he must have known Kwok had met a tragic death – for which Yim was responsible – and that the properties he received had been stolen. Wei told the jury not to speculate on why Yim was not on trial. “Ultimately, it is for you to decide whether the prosecution successfully proves the charges,” he said. The trial continues before Madam Justice Judianna Barnes on Thursday.