An out-of-hours doctor who killed a 70-year-old man by injecting him with an overdose of a painkiller could repeat the error, a panel has warned. Nigerian-born Dr Daniel Ubani, 67, injected David Gray, of Manea, Cambridgeshire, with 10 times the recommended dosage of a painkiller. A General Medical Council (GMC) panel is holding a hearing into the case. The panel said Dr Ubani's actions had "brought the profession into disrepute" and questioned his clinical competence.