Police are treating the death of a 23-year-old man in south-east London as “unexplained” after he is said to have taken part in an online punching game. The post-mortem, carried out at Princess Royal Hospital in Bromley, was inconclusive and toxicology tests have been ordered. The internet game Mr Main is thought to have been playing is called Punch4Punch. It involves two people taking it in turns to hit each other, until one gives up. Sometimes alcohol is drunk as a penalty. The fight is often videoed and then posted online.