In the dock: Victorino Chua, 49, has given evidence for the first time and denied he murdered three and poisoned 18 more at Stepping Hill Hospital in Stockport . A nurse today told a jury he did not murder three hospital patients and poison almost 20 others on his ward by contaminating their medicine with insulin. Victorino Chua, 49, has given evidence for the first time  and denied he tampered with saline bags and ampoules  at Stepping Hill Hospital in Stockport in order to kill and injure people he was caring for. Chua denies murdering patients Tracey Arden, 44, Arnold Lancaster, 71 and Derek Weaver, 83, and deliberately poisoning 18 others between 2011 and 2012. The prosecution claim the defendant changed tack in January 2012 amid an ongoing police investigation and increased security when he deliberately altered drug dosages on prescription charts. His barrister, Peter Griffiths QC, today told the defendant that he would ask him some questions about his family and personal life but first would ask specific questions about the charges he faces. Focusing first on the events of summer 2011 at the Stockport hospital, Mr Griffiths said to Chua:'My first question to you is did you ever at any time contaminate any medical product with any insulin?' Chua replied: 'No sir.' Turning to the charges he murdered patients Tracey Arden, 44, Arnold Lancaster, 71, and Derek Weaver, 83, Mr Griffiths asked: 'As far as those three patients, deceased now of course, it is not suggested in this case that they were in your care at material times but I must ask ask this question, did you ever intend to kill those patients?' Chua said again: 'No sir.' Mr Griffiths said: 'Did you ever intend to cause those patients, or any patient, serious harm - that is grievous bodily harm?' Chua replied: 'No sir.' Chua has pleaded not guilty to 36 charges in all, including three alleged murders, one count of grievous bodily harm with intent, 23 counts of attempted grievous bodily harm, eight counts of attempting to cause a poison to be administered and one count of administering a poison. Deaths on the ward: (Left to right) Patients Tracey Arden, 44, Arnold Lancaster, 71 and Derek Weaver, 83, were all allegedly murdered by their nurse . Allegations: Chua is accused of killing three patients at Stepping Hill Hospital in Stockport, pictured, by injecting medical products with insulin . He also told Mr Griffiths in relation to two counts that he had not contaminated a bottle of antibiotics with insulin or contaminated a saline bag with a drug named Lidocaine. Addressing the January 2012 charges, Mr Griffiths said to the witness: 'The underlying and fundamental allegations laid against you by the prosecution is that you altered the prescription charts of patients. My question is this, did you alter any of those prescription charts?' Chua replied: 'No sir.' Mr Griffiths said: 'In each of these counts, there is an added ingredient that you had an intention to injure, aggrieve or annoy. Did you ever intend to injure, aggrieve or annoy any patient?' 'No sir,' said Chua. Then he was asked about a specific alleged victim, Gillian Millar, who he is said to have attempted to administer poison to in January 2012. Mr Griffiths said: 'Gillian Millar, her prescription chart was not altered but it is alleged by the prosecution that you offered some sort of unprescribed medicine to that lady after she arrived on the ward. Did you do so?' The Filipino father-of-two replied: 'No sir.' Yesterday his trial heard he had warned there was ‘a devil’ in him in a letter, a jury heard yesterday. Document: Extracts from the 13-page note show that Chua wrote about 'a devil in me', going 'straight to hell' and being 'an evil person' making a 'bitter nurse confession' Victorino Chua penned what he called a ‘bitter nurse confession’ in which he spelled out ‘how an angel can turn to an evil person’. In 13 pages of rambling, broken handwritten English, the Filipino nurse said he might ‘explode’ at any time, adding: ‘If I will be pushed, they gonna be sorry.’ His lawyers say the document – found in his home following his arrest – is not a criminal confession but an ‘outlet for his anger and frustration’ written at the suggestion of a counsellor 12 months before the first alleged poisoning. But questioned by detectives after his arrest for changing patients’ prescriptions on the wards, the 49-year-old said: ‘Sometimes I snap’. Dependant on painkillers, sleeping tablets and antidepressants, Chua also wrote that he sometimes felt like killing himself, but feared he would ‘go straight to hell no questions asked’. Chua denies murder as well as 24 counts of attempting to cause grievous bodily harm with intent, eight of attempting to administer poison, one of causing grievous bodily harm with intent and one of administering poison. The trial continues. Sorry we are not currently accepting comments on this article.
Victorino Chua, 49, denies murdering patients at Stockport hospital in 2011 .
Filipino nurse also accused of poisoning 18 more at Stepping Hill hospital .
Denies injecting insulin and other poisons into bags of medicine on ward .