A male nurse arrested by detectives investigating the Stepping Hill Hospital poisonings was named by sources yesterday as Victorino Chua.
Chua, 46, was arrested at his Stockport home on Thursday by officers from Greater Manchester Police. He is being questioned on suspicion of unlawfully administering or causing a person to take a noxious substance, or poison, after it was found that medical records were tampered with on Monday and a patient given incorrect medicine.
The patient was monitored and subsequently discharged.
Yesterday a spokesman for Unison, the public sector trade union, confirmed Mr Chua is a member.
Sources close to the investigation stressed the his arrest formed part of a separate probe into four deaths of poisoned patients at the Stockport hospital, and as yet there was no link between the two.
Chua worked on the same wards at the time the patients were poisoned last summer. He was held after another nurse noticed the medical records of a patient on Ward A3 were altered overnight between January 2 and 3.
The patient whose records were altered was given medicine he should not have received but was not harmed.
Assistant Chief Constable Terry Sweeney said: “This is, and always has been, a search for the truth.
“It is due to the diligence of staff at the hospital that we were made aware about the potential tampering of medical records and everyone should be reassured that, like the hospital, we initiated a swift response.”