TOKYO: Japanese police are probing the deaths of 46 patients on the same floor of a hospital where a pair of elderly men were fatally poisoned, reports said on Monday. The two men’s post-mortem determined they’re cause of death by a chemical found in disinfectant, public broadcaster NHK and other media reported earlier. Police reportedly suspect the chemical was injected into drips administered to the two 88-year-old victims – Sozo Nishikawa and Nobuo Yamaki. But the probe has grown with authorities looking at how almost four dozen others died at the hospital since early July – although some were already seriously ill. Hospital staff reportedly found puncture marks in 10 intravenous bags stored near the nursing station on the same floor. Many have already been cremated, making it hard to determine the cause of death, reports said and added that neither police nor the hospital would confirm the news reports as no suspects have been named. The investigation comes two months after the murder of 19 people at a centre for the mentally disabled – Japan’s worst killing spree in decades. In 2000 a male nurse was charged with killing one patient and attempting to murder four others by poisoning them at a clinic in the northern Japanese city of Sendai.