The chairman of a review into the treatment of NHS whistleblowers said he had heard "shocking stories" about staff too afraid to speak out and who felt suicidal after their concerns were ignored.
Sir Robert Francis QC said he heard "time and time again" from NHS staff who were "bullied" after raising concerns about poor patient care.
Sir Robert told the BBC before the review's publication, "I've heard some frankly shocking stories about [staff] whose health has suffered, and in rare cases who've felt suicidal as a result of their perception of them being ignored or worse."
The findings of a major report into how to create a more open NHS culture will be released today.
Sir Robert Francis QC was asked by the Health Secretary to carry out the Freedom to Speak Up Review to recommend how best staff can be supported to raise concerns about poor patient care amid concerns that this has gone undetected because warnings from staff were quashed.
Sir Robert, who led two major inquiries into failures at Mid Staffordshire NHS Foundation Trust, said at the time of the review being announced last June that the two previous probes had shown the "appalling consequences for patients when there is a 'closed ranks' culture".
"We need a culture where 'I need to report this' is the thought, foremost in the mind of any NHS worker that has concerns - a culture where concerns are listened to and acted upon," he said.
An estimated 450 deaths MAY have been prevented at 11 NHS trusts after they were put into special measures, a new report has found.
Healthcare analysts Dr Foster found there had been a "significant reduction" of nearly 10% in the overall death rate at the 11 trusts, compared with a national average fall of 3.3%.
Tameside Hospital NHS Foundation Trust was the only trust to buck the trend, reporting 1,200 deaths compared with 914 in 2013.
Burton Hospitals NHS Foundation Trust, Medway NHS Foundation Trust and Sherwood Forest Hospital NHS Foundation Trust still had "higher than expected" death rates at the end of the 2013/14, the report said.
Roger Taylor, Dr Foster's director of research and public affairs, said: "Our analysis gives us some hard evidence that special measures can be an effective tool for turning around NHS trusts that experience problems."
An investigation looked at 150 NHS complaints regarding allegations that patients had died or suffered avoidable harm because of failings in their care. It found that 28 of the 150 cases should have been investigated by the NHS as a Serious Untoward Incident (SUI), which is triggered to allow doctors to learn from past mistakes.
Investigations weren't carried out when they should have been and when they were carried out they did not find out or explain why failings happened.
When people make a complaint that they have been seriously harmed they should expect it to be taken seriously and thoroughly investigated.
Parliamentary and Health Service Ombudsman, Julie Mellor, said there is "significant variation" in the quality of NHS investigations. But in the vast majority of these cases (71%) the hospital failed to carry out an SUI.
The chief executive of the patients' group Healthwatch England has said that "tens of thousands of patients are being failed" by the NHS complaints system.
The Ombudsman's findings are worrying but sadly not surprising.
Our research shows that tens of thousands of people every year are being failed by the NHS and yet never report it because they have no faith the complaints system will make any difference.
What we need is a complete overhaul of the complaints system that ensures every incident is properly investigated and learnt from, and that those affected are treated with the dignity they deserve.
Patients who complain about their care are being let down by "appalling" NHS investigations, a highly critical review has found. More than a third of probes into deaths or avoidable harm at hospitals were found to be "inadequate", according to an investigation by the Parliamentary and Health Service Ombudsman (PHSO).
Families interviewed for the review complained they felt "belittled" and "misled" by medical staff who failed to listen to their concerns or give them straight answers. Patients groups said the findings are "worrying" and suggest the lessons from recent hospital scandals have not been learnt.
The number of patients waiting for more than four hours in English A&E departments increased last week as snow and cold weather pushed up attendances.
Figures from NHS England showed 92.3% of patients were admitted, transferred or discharged within the target time - down from last week's 93%.
It was the 18th successive week that the goal of 95% was missed.
Accidents and falls linked to the cold weather contributed to an 11,000 increase in the number of people turning up at A&E, which reached 401,000 in the week ending February 1, but still below the peak of 440,000 experienced before Christmas.
Billions of patient cash was wasted on "misguided" reforms which have left the NHS worse off than it was in 2010, a think-tank claims.Read the full story ›
Ed Miliband has been accused of deliberately scaremongering and trying to frighten people about the future of the NHS in North Staffordshire by David Cameron.
The Prime Minister branded the Labour leader's behaviour a "disgraceful tactic" and criticised again his alleged use of the word weaponise in relation to the health service.
Mr Cameron was responding to a question from Labour's Joan Walley about the release of a KPMG report into the state of the Staffordshire NHS.
I know that the University Hospitals of North Midlands NHS Trust are working hard with the Trust Development Authority and other parties involved to manage a safely and timely transition of services. All parties should work together to do that.
But I have to say it is not helped by the Leader of the Opposition going to Stafford and deliberately scaremongering and trying to frighten local people.
He has said that North Stafford Hospital is on the 'road to closure'. This is what he means by weaponising the NHS. It is an absolutely disgraceful tactic. You know it's not true, he knows it is not true but he hasn't got the gumption to say so.