A former trainee psychiatric nurse arrested over a claim he had sex with a patient at Carlisle's former Garlands psychiatric hospital will not be prosecuted.

Penrith man Tom Bell has spent years fighting to achieve justice for his sister Alison, who was just 25 when she took her own life in 1991.

She began a relationship with the unnamed nurse which continued after she was discharged. She became pregnant and had a termination before killing herself three years later.

Cumbria Police launched their own investigation after the NHS trust involved apologised in 2002 for its “inadequate supervision”.

The CPS has now confirmed the former trainee male nurse involved, who has not been publicly named, will not be prosecuted. Mr Bell, a university project manager from Penrith, has called for the decision to be reviewed.

Joanne Cunliffe, head of the CPS north west rape and serious sexual offences unit, told the News & Star : “Following careful consideration we have decided not to bring any charges in relation to this case.

“A specialist CPS lawyer reviewed all the evidence in accordance with the Code for Crown Prosecutors. We concluded that while the evidential test set out in the code was met, a prosecution would not be in the public interest.”

Miss Bell was diagnosed with paranoid schizophrenia in the 1980s and admitted to the Garlands clinic in Carlisle, now superseded by the Carleton Clinic.

Cumbria Police and the CPS have not confirmed what potential offence the man was arrested for , though under Section 128 of the Mental Health it is a criminal offence for a nurse to have sexual relations on hospital premises .

Mr Bell recently received a letter from Supt Sarah Jackson, at Cumbria Police, acknowledging shortcomings in the investigation.

“Cumbria constabulary could have, and should have, done more, and we let you and your family down,” she wrote.

“I would like to acknowledge in full that we did not pursue all of the lines of inquiry that we should have during the initial investigation that occurred in 2001, resulting in a flawed investigation.”

In 2002 Miss Bell's family gave the force her medical records, a certificate of the pregnancy termination and a copy of the apology from Nigel Woodcock, who at the time was the trust's chief executive.

The Bells later learned these documents had gone missing and asked for the investigation to be reopened in 2015. The force have now also admitted the initial file presented to the CPS in 2001 was lacking in evidence.

Mr Bell said: “We were really surprised when we were told initially that the male nurse who we feel abused his position of trust would not face any action.

“Now, we know that evidence we gave to the police was lost and therefore the CPS did not have everything they needed to make an informed decision. The mind absolutely boggles at how this could happen. I am utterly shocked.”

In a more recent statement the trust said it was not currently conducting an internal inquiry but was collaborating fully with the police investigation.

Reacting yesterday, Mr Bell, 49, described the CPS decision not to prosecute as “very poor”.

“We are in a post-Savile era,” he said. “And only last weekend Cumbria Police were publicly encouraging people to come forward with information about historical sexual offences, saying we'll take you seriously.

“They [the CPS] are sending out the kind of decision you'd expect in the 1970s, or 80s, not 2017. They've also acknowledged in a letter to us that they believe there is evidence to suggest people at the Garlands knew what was going on.

“In other words, it was a culture where this was condoned.

“So are they trying to say that in a culture where this was condoned that Alison was an isolated incident? Ideally, we'd like the CPS to review this decision.”

The CPS has said the decision does not meet the criteria to be reviewed.

Asked what kind of person she was, Mr Bell added: “Alison was a deeply religious, gentle person. If she'd got the help she needed she might have survived.

“But she came out of the Garlands more damaged than when she went in.”

A spokeswoman for Cumbria Partnership NHS Foundation Trust, the NHS body which now runs the Carleton Clinic in Carlisle, said: “Since the 1990s, mental health services in the county have been the responsibility of a number of organisations which no longer exist.

“It is currently the responsibility of Cumbria Partnership NHS Foundation Trust and we have been cooperating fully with the police and assisting them, where we are able to, with their enquiries into this case. We are committed to ensuring that the services we provide offer the best possible care that we can.”