Two more patients whose saline drips were allegedly contaminated with insulin at a British hospital died Thursday, bringing the total number of deaths to five, as police continued to question a nurse arrested on suspicion of murder.

Assistant Chief Constable Ian Hopkins told Sky News, "I can confirm that there have been two further deaths that we are linking to the investigation into deliberate contamination of medical products at Stepping Hill Hospital."

He said that an 83-year-old man died Thursday morning, and an 84-year-old woman died July 14. An autopsy was undertaken on the woman's body, and the case was referred to a Home Office pathologist for a further examination.

Hopkins described the case as "complex" and said that police were still awaiting the results of medical tests to confirm the causes of all five deaths.

"As with the deaths of George Keep, Arnold Lancaster and Tracey Arden, the cause of this man and woman's death is not known, and it is important we do not lose sight of this fact," he added.

A 41-year-old man also believed to have been poisoned with the contaminated medicine remained in critical condition Thursday.

Fourteen patients at the hospital were given the tainted saline solution. Arden, 44, died July 7, while Arnold Lancaster, 71, and George Keep, 84, who both had serious health problems, died last week, apparently as a result of the poisoning.

The nine other patients who were affected by the tampered medication recovered, including one woman who had a seizure after the contaminated saline was directly injected into a drip she was hooked up to.

A 27-year-old female nurse who works at the hospital was arrested early Wednesday on suspicion of murder. Named as Rebecca Leighton, from Heaviley in Stockport, northern England, she describes herself on Facebook as a "happy go lucky kinda gal."

She was still being questioned by police Thursday as crime scene investigators examined her apartment, about a mile from the hospital where the saline containers were contaminated.

The Nursing and Midwifery Council (NMC) confirmed that Leighton was arrested.
NMC chief executive Professor Dickon Weir-Hugh said, "We have commenced fitness to practice proceedings with a view to suspending her from the register as quickly as possible."

Medics at the hospital were being made to work in pairs, and security guards were monitoring access to medicines following the realization that the saline containers had been tampered with.

The alarm was first raised July 12, after multiple sclerosis patient Arden died.