ONE of the survivors of killer nurse Benjamin Geen has called for an independent investigation to discover why it took so long to discover there was a murderer working on the ward.

At Oxford Crown Court last week, Geen, 25, from Banbury, was convicted of murdering two patients and causing grievous bodily harm to a further 15 patients while working in A&E at the Horton Hospital.

The twisted former Territorial Army soldier got his kicks by injecting patients with a variety of drugs that caused them to stop breathing. The incidents all occurred between December 2003 and February 2004.

During the trial the prosecution said that unexplained respiratory arrests were rare, but it was only after the case of Timothy Stubbs Geen's 17th and final victim that an investigation took place.

Robert Robinson, 55, of Oxford, who was Geen's third victim, has now demanded that health chiefs should conduct an independent inquiry to find out how Geen was able to poison so many patients before suspicions were formally raised.

Mr Robinson said: "I certainly think an inquiry has got to be looked at. How was this guy able to get his hands on prescribed drugs for so long without other people knowing?

"He had already made comments to staff on the lines of 'It's amazing that every time I work someone has a respiratory arrest'. Why did it then take so long for staff to investigate the matter further?"

Banbury MP Tony Baldry has backed Mr Robinson's call for an independent inquiry, and said he is writing to Oxford Radcliffe Hospitals NHS Trust chief executive Trevor Campbell Davis.

Mr Baldry said: "The trust may say it all happened over a period of a few months, but the fact that these are such rare occurrences makes me wonder whether questions could have been raised earlier. It was difficult to investigate these things when there was a court case happening, but now that is out of the way, I would have thought it would be sensible for a short independent inquiry to take place. There may be lessons which could be learned for the trust as a whole."

Following Geen's arrest on February 9, 2004, an internal inquiry was immediately conducted at the Horton Hospital, and a report completed by September 2004.

This included looking at the way notes were recorded by doctors and nurses and the accessibility of drugs.

A further investigation was carried out by the Central England Audit and Consultancy board between November and December 2005 which made additional recommendations.

Helen Pegg, spokesman for the Oxford Radcliffe Hospitals NHS Trust, said: "Our feedback from the police was that the investigation was thorough and there was no way it could have been picked up any quicker."