Three nurses who are suspects in a police homicide inquiry are still employed by Counties Manukau District Health Board. A coroner’s inquest into the death of Auckland woman Heather Bills wrapped up in the Auckland District Court on Friday. Bills died in 2013 while in the care of Middlemore Hospital, having survived an explosive fire at her Ōrākei home six weeks earlier. Michele Maher, Heather Bills’ daughter, questioned witnesses at the inquest into her mother’s death. Neighbours rescued the 64-year-old from the blaze and she was admitted to hospital with serious burns. Six weeks later, however, she was dead, after suffering an irreversible brain injury caused by a large dose of insulin. The person who administered the insulin dose to Bills remains a mystery. During the inquest, police revealed they have three suspects in their own investigation, all of whom are nurses that worked on Bills’ care. Nurses who were witnesses at the inquest gave conflicting accounts of what happened the night she suffered the fatal brain injury. The inquest was also told Bills had offered to pay hospital staff to end her life. On Friday, a spokeswoman for Counties Manukau DHB confirmed it still employs all three nurses. “In 2013, when Ms Bills died, the police conducted a full investigation including interviewing the staff who had contact with Ms Bills,” the spokeswoman said. “The police investigation did not result in a prosecution of any individual. The DHB was also never advised that the police had any particular concerns about the acts or omissions of any particular individual.” Through the coronial process, the DHB had learnt for the first time that police had three suspects, and it had no proof of wrongdoing by any of those staff, the spokeswoman said. “The DHB has obligations to be a good employer in accordance with the State Services Act and must follow all the requirements of the laws protecting employees in New Zealand. “In the absence of any proof of wrongdoing, the DHB could not take action against an employee.” The spokeswoman added: “The DHB is co-operating with the coroner’s process, as it did with the police investigation. “If further information comes to light through the inquest process, or any other route, the DHB will consider that information and if appropriate will act on it.” On Wednesday, the DHB apologised over Bills’ death, and revealed it wasn’t until a number of days later that the possibility of homicide was raised. The acting chief executive of the DHB, Gloria Johnson, who was chief medical officer of the DHB when Bills died, gave evidence at the inquest. “I do want to take the opportunity to say how incredibly sorry I am, and I want to apologise on behalf of the DHB,” Johnson said to Bills’ daughter, Michelle Maher. Johnson added she still did not know how Bills came to be given the fatal dose. In recent years, there has been a spate of insulin murders in Australia. The coroner reserved her findings on Friday.