Labour MP Ann Clwyd has called for the chair and chief executive of Cardiff and the Vale Health Board to resign, claiming details of the investigation into her husband's death were released "for spiteful and political reasons".
ITV News Social Affairs Editor Penny Marshall wrote on Twitter:
Ms Clwyd has been campaigning for better treatment of hospital patients since she complained that her own husband was neglected before his death at the Heath Hospital in Cardiff.
Labour MP Ann Clwyd, who led today's critical report of the way the NHS handles complaints, said the review team expects significant improvements with a year.
She said around 30 organisations have made promises to act on today's recommendations.
A review into the NHS complaints system has concluded that there must be a "revolution".
The report, led by Labour MP Ann Clwyd, found that people think there is a "lack of independence" in the current system, with the way many hospitals handle complaints akin to "marking their own homework".
Patients and their families are reluctant to complain about bad care and hospitals are too "defensive" to hear and address concerns, the review found.
The report concluded that it should not be "painful or difficult" to complain about poor care. It made a string of recommendations from patients' bedsides to hospital board room.
The law firm that represented a woman who spent eight years fighting for the NHS to explain why her father died following poor care at a Worcestershire hospital has welcomed the upcoming review into the complaints system.
Leigh Day said that the report is "well overdue", adding that some of its clients have spent up to six years trying to get a response to their complaints.
A woman who had to wait eight years for an NHS explanation of why her father died as he received poor care at a Worcestershire hospital has said the NHS complaints system must "fundamentally change".
Pauline Robles' 85-year-old father died nine days after being admitted to Alexandra Hospital in Redditch, after the hospital failed to administer any of the heart medication he had been taking for more than 20 years.
Following an eight-year battle to get the answers she and her family needed, they finally received a letter of apology in January this year, after involving solicitors.
A review into how the NHS handles complaints is due to be published.
Led by Cynon Valley Labour MP Ann Clwyd, the government-backed report was set up in the wake of the scandal at Mid Staffordshire NHS Foundation Trust.
Ms Clwyd publicly protested last year about the poor care her late husband received while in hospital. She told the BBC he had died "like a battery hen" at the University Hospital of Wales in Cardiff.
Labour MP Ann Clwyd has called for an inquiry into failings at Wales' biggest hospital and called it the Welsh equivalent of the Mid-Staffordshire Hospital scandal, in an interview with the BBC.
Ann Clwyd MP has spoken to Daybreak about her anger and grief at the care received by her dying husband at University Hospital of Wales in Cardiff.