Staff were accused of launching a ‘witch hunt’ to track down the person who sent an anonymous letter telling a widower about blunders in his wife’s treatment.

Susan Warby, 57, died in August 2018 at at West Suffolk Hospital in Bury St Edmunds five weeks after she had bowel surgery.

She had suffered a series of complications in her treatment.

An inquest heard her family received the letter in October 2018 highlighting errors in her surgery.

Both Suffolk Police and the hospital launched investigations into where the letter came from at the request of the coroner.

The hospital said that an investigation into the nature of Mrs Warby’s care was already under way at this point.

Investigations into the letter confirmed that there had been issues around an arterial line fitted to Mrs Warby during surgery, Suffolk’s senior coroner, Nigel Parsley, said.

Doctors were reportedly asked for fingerprints as part of the hospital’s investigation, with an official from trade union Unison describing the investigation as a ‘witch hunt’ designed to identify the whistleblower who revealed the blunders.

The Times said that staff were also asked to provide handwriting samples.

They reported claims that the hospital spent £968 on a handwriting expert and £1,512 on a fingerprint expert.

Yesterday’s inquest was told that Mrs Warby had complained of abdominal pain, vomiting and diarrhoea for around a fortnight before she collapsed at home on July 26 2018 and her husband, Jon Warby, called the NHS 111 number.

The mother, known as Sue, was taken to hospital by ambulance and underwent emergency open surgery for a perforated bowel the next day, on July 27.

Mr Parsley said Mrs Warby was too unwell for her surgical incisions to be stitched up after the surgery and this was eventually done on July 29.

Former police officer Mr Warby said, in a statement read by Mr Parsley: ‘Following the operation, Sue’s stomach was left open and she was taken to the intensive care unit.’

He said he was told that his wife was also suffering from a ‘rampant infection’ which was putting a strain on her kidneys.

Mr Warby said he was told that, during his wife’s operation, an arterial line was fitted with an intravenous (IV) infusion to keep it clear.

Mrs Warby was incorrectly given glucose instead of saline, Mr Warby said.

‘I asked what the effect of this could be and the consultant told me brain damage or death,’ he said, adding that he was later told there was ‘no new irreversible brain damage’.

He said his wife’s condition was ‘very up and down’ in the following days and her arterial line was replaced with a line into a central vein on August 7.

During this operation, Mrs Warby suffered a punctured lung.

Mr Warby said he was told it ‘could be a very tricky procedure’ but that it was carried out by a ‘junior’ member of staff.

‘I’m concerned that a consultant should have performed the procedure due to her being critically ill,’ he said.

He said that, a week later, Mrs Warby contracted a fungal infection and the family agreed to withdraw active treatment.

Mrs Warby’s medical cause of death was recorded as multi-organ failure, with contributory causes including septicaemia, pneumonia and perforated diverticular disease.

The inquest heard that she had been diagnosed with the digestive condition diverticular disease in 1997.

Consultant surgeon Dr Amitabh Mishra, who operated on Mrs Warby, said: ‘Given how unwell she was, it was decided to proceed directly to an open operation.’

He said she was assessed as having an 84.8% risk of mortality, taking into account her underlying factors including her hypertension and that she was a smoker.

Paul Morris, the hospital’s deputy chief nurse – who oversees the patient safety team, said that a serious incident report was carried out.

The report found that there was no evidence that the mix-up of glucose and saline had an impact on the outcome in Mrs Warby’s case, the inquest heard.

‘We know Mrs Warby was very unwell but we know there are things that did go wrong in her care,’ said Mr Morris.

‘We think it’s unlikely to have been the sole cause (of her death) but she was very unwell.’

He said there was a separate incident 12 hours earlier which was reported, relating to confusion over fluids.

The hospital has made a number of changes following the incident, he said, including changes to the labelling on fluid bags in an effort to make the difference clearer.

The inquest, listed for two days, continues.