The health secretary Matt Hancock has repeatedly failed to respond to concerns that his local hospital is bullying and intimidating senior doctors to prevent them raising serious issues of patient safety, the Guardian can reveal.

Doctors at West Suffolk hospital have complained of harassment after trust bosses demanded they give fingerprints as part of a “witch-hunt” to identify staff members who blew the whistle on potentially botched surgery.

The family of Susan Warby, who died five weeks after an operation in August 2018, was sent an anonymous letter highlighting errors in her procedure.

After conducting a serious incident investigation into her treatment, the trust threatened senior medics with possible disciplinary action if they failed to give their fingerprints and samples of their handwriting.

The trust insisted this request was not threatening but a note to staff warned that refusal to consent “could be considered as evidence which implicates you in writing the letter”.

Consultants at the hospital, in Bury St Edmunds, are so angry at the threats and what one called a “culture of bullying from the top down” that they have written to the trust’s chairwoman raising “grave concerns”. They accused the management team of denying staff the freedom to speak about their concerns over care, which has been an enshrined right for NHS staff since the Mid Staffordshire scandal.

Details of the treatment of staff have been passed to Hancock. However, he has rebuffed on three occasions attempts to discuss the deep-seated problems at the trust with those who have raised concerns, including a senior clinician who was asked for fingerprints.

His refusal to engage threatens to undermine his claims to be a champion of NHS whistleblowers. Earlier this year he tweeted his determination “to end the injustice of making NHS staff choose between the job they love & speaking [to] the trust to keep patients safe”.

Matt Hancock (@MattHancock) Whistleblowers perform a vital & courageous service for the NHS. I’m determined to end the injustice of making NHS staff choose between the job they love & speaking the truth to keep patients safehttps://t.co/26WrWE9DzQ pic.twitter.com/yt6wivU6Z0

The hospital’s hunt for the whistleblower also raised questions about the trust’s chief executive, Stephen Dunn, who was given a CBE for “services to health and patient safety” last year.

The trust’s medical director, Dr Nick Jenkins, accused the anonymous letter-writer of trying to “weaponise a patient” during a staff medical committee meeting in October.

Dr Rinesh Parmar, chair of the Doctors’ Association UK, which campaigns to improve doctors’ working conditions, said: “These are utterly extraordinary and unprecedented behaviours from an NHS trust that fly in the face of everything learned from Mid Staffs. Threats, secrecy and a toxic culture towards dedicated NHS staff where whistleblowers are persecuted serve only to move us further away from a just culture and threaten patient safety.”

Dan Sharpstone, a consultant gastroenterologist at the hospital who is also Suffolk’s assistant coroner, suggested to the staff medical meeting that the letter-writer could have approached the family because the hospital’s procedures “don’t work”, and he was worried that “every whistleblower will now be treated like this”.

The trust’s hunt for the whistleblower comes after senior doctors expressed concern about an earlier potentially botched operation. After conducting a serious incident investigation, the trust accepted that its care of that patient was substandard.

The “defensive” response of management to both cases, and others, has alarmed doctors who, in a meeting in September, accused hospital bosses of trying to “protect themselves and the trust’s reputation at the expense of consultants”.

An email sent to Hancock in September by Victoria Sutton, a family friend and concerned local resident, said: “You probably know about … the felled clinicians at West Suffolk, the fingerprint and handwriting demands from the executive. Madness.

“The costs involved in all these ETs [employment tribunals], the anaesthesia department at WSH is running on skeleton staffing, is exponential.”

One doctor who was asked to provide fingerprints emailed Hancock requesting a meeting. His office acknowledged receipt of it, but did not follow it up with him.

Minutes of the doctors’ meeting in September outlined the “widespread concern and obvious distress of some consultants” about the “behaviour of the senior management team”. It said the management investigation was “intimidating and harassing and totally at odds with the trust’s stated commitment to a culture of openness and speaking up”.

On 10 September, the committee then sent a letter to the trust chair, Sheila Childerhouse, expressing “grave concerns … raised by multiple departments in regard to the culture and behaviours within the executive body of the trust, which have not seemed to endorse the trust values of freedom to speak”.

The trust has a policy of encouraging whistleblowers, but one doctor told the Guardian: “There’s a culture of bullying at the trust from the top down, and the bullying has been normalised and has trickled all the way down.”

The doctor added: “Letters telling people to be fingerprinted are appalling. Doctors feel the [Warby] case wasn’t investigated properly and what’s happening now is a witch-hunt to find out who wrote the letter.”

Another said: “There are several deaths that are with the coroner where staff have pointed out care has been very poor, and they have been bullied horrifically and threatened. The culture in the institution is of bullying and covering up anything that is not glowing towards the hospital.”

Sutton said that a doctor had told her: “It is totalitarian, they just spew out a policy of good news. It is like North Korea and you are not allowed to complain.”

As MP for the neighbouring seat of West Suffolk, Hancock has close links with the hospital and made his first speech as health secretary there, praising it as one of the best in the country. Four months after Warby’s death, Dunn was awarded his CBE, prompting congratulations from Hancock.

Dr Steve Dunn (@SteveDunnCEO) Genuinely Matt thanks for your lovely words and your local support as an outstanding local MP. Doing a brilliant job as Secretary of State in interesting times! pic.twitter.com/flmuputOR6

An inquest into Warby’s death will be held next month.

Warby’s family is planning to sue the trust for medical negligence after she was operated on for a burst bowel five weeks before her death.

Her husband, Jon Warby, said: “I have instigated a claim for medical malpractice. I am not happy how things were done, but the rest will have to wait until after the inquest.”

Her father-in-law, Frank Warby, said: “My son got a letter from somebody anonymous saying there was a whole catalogue of errors.”

A West Suffolk NHS foundation trust spokeswoman said: “Any allegations of bullying are taken extremely seriously and are thoroughly and urgently investigated, which is one of the reasons why we are among the top five NHS trusts in the country for having engaged, happy, and empowered staff.”

“In this case we shared our serious incident investigation process with the CQC [Care Quality Commission], and the NHS national head of whistleblowing, who backed our approach.”

Hancock’s office insisted he had taken up his constituent’s concerns with the hospital, but did not explain why he had failed to address the doctor’s concern. His response also replicated the trust’s statement to the Guardian.