A 60-year-old woman, believed to have been poisoned by contaminated saline at a hospital, has died, police said today.
The patient was among those thought to have suffered hypoglycaemic episodes between June and July last year after being administered contaminated products at Stepping Hill Hospital in Stockport.
Police are currently investigating the deaths of four other patients in the complex and long-running investigation.
The woman, who has not been named, died in the early hours of Saturday January 14.
A spokesman for Greater Manchester Police said: "We have been made aware of the death of a 60-year-old woman at Stepping Hill Hospital.
"The coroner has been made aware and further tests are ongoing."
Tracey Arden, 44, Arnold Lancaster, 71, and Derek Weaver, 83, died shortly after experiencing similar hypoglycaemic episodes.
All the deaths took place on wards A1, A2 or A3 - acute care wards caring for seriously ill patients.
Police are looking into whether the alleged poisoning of William Dickson, 82, at the hospital during the summer was also a factor in his death.
The former journalist, of Cheadle Hulme, Cheshire, died on New Year's Eve.
The latest victim announced today was one of 21 patients believed to have been deliberately poisoned.
The cases of a further 21 patients who suffered hypoglycaemic episodes are not being treated as suspicious.
Earlier this month, a 46-year-old male nurse suspected of murdering three patients at Stepping Hill Hospital was released on police bail until April pending further inquiries.
Victorino Chua was arrested on suspicion of tampering with medical records and was then further arrested on suspicion of three counts of murder and 18 counts of causing grievous bodily harm.
He was quizzed over the contamination of saline drips which caused patients' blood sugar to fall.
Police chiefs have previously stressed that detectives have not established the degree to which deliberate contamination of products may have contributed to the patients' deaths.
About 650 people have already been spoken to by officers during the investigation at the hospital since the saline drip contamination was discovered.