Cases where Disabled people claiming benefits died or came to serious harm have led to more than 150 government reviews since 2012, a BBC investigation has found.
Internal reviews are held by the DWP when it is alleged its actions had a negative impact, or when it is named at an inquest.
The BBC investigation also reveals that 82 claimants to have died after some alleged DWP activity such as termination of benefits.
It says that mental health vulnerabilities were a contributing factor in 35 of those people's deaths.
Three families of Disabled people who have died - Philippa Day, Errol Graham and Jodey Whiting – are hoping to take the DWP to court in separate cases within weeks.
Philippa Day was found collapsed at her home beside a letter rejecting her request for an at-home benefits assessment in August 2019.
Ms Day who had been diagnosed with unstable personality disorder, had previously said her benefit claim left her feeling "inhuman", her sister told the BBC.
An inquest concluded in January 2021 that authorities made 28 errors in managing her case.
The assistant coroner issued a so-called Prevention of Future Death (PFD) report to the DWP and private contractor Capita, requiring them to explain what action they might take to improve.
That was the fourth PFD sent to the DWP by coroners since 2013.
Errol Graham starved to death in 2018 while seriously mentally ill. His benefits were stopped when he failed to attend a work capability assessment and did not respond to calls, letters or home visits from the DWP.
When his body was found, Mr Graham weighed four-and-a-half stone (30kg) and his family said he had used pliers to pull out his teeth.
His family submitted an application for permission to go to the Court of Appeal in April, after losing a judicial review against the DWP's safeguarding policy.
Jodey Whiting took her own life after her benefits were stopped.
Her family are due to attend the High Court on 22 June to argue she should have a second inquest to consider the DWP's role in her 2017 death.
Ms Whiting's mother, Joy Dove won permission to request the new inquest. New evidence was submitted including an independent inquiry's conclusions that mistakes were made by the DWP.
Michael Buchanan BBC social affairs correspondent said:
“It's been 11 years since the government was first made aware there was a problem with the tests it used to assess benefit claims after a coroner wrote to the DWP following the suicide of a man.
During all that time, the government has simply marked its own homework, doing internal reviews.
In a clear sign that these assessments are of limited use, in Scotland from next year, claimants for the main disability benefit will only have to undergo a test if any doubts remain about their claim following a review of their medical records.
For the vast majority of people, the expectation is that they won't have to undergo a test - removing from the process what has long been a source of extreme stress for many people.
In 2012, internal reviews by the DWP took the form of so-called "peer reviews" and the DWP carried out "60 peer reviews following the death of a customer" between February 2012 and November 2014, according to the Disability News Service.
Since 2015, the DWP has held so-called "internal process reviews" instead. In July 2019 Justin Tomlinson MP, Minister for Disabled People, Health and Work said there had been 84 held since 2015 and a further six would be "conducted shortly".
The reviews are not routinely published and bereaved families are not routinely informed when they begin."
Calling for an independent inquiry, Labour MP Debbie Abrahams said she thought the known cases were "the tip of the iceberg" and that any investigations needed “to be taken out of the hands of the DWP."
She added that “there has been such a lack of openness and transparency to enable us to properly examine reports on all deaths is a disgrace."
Ms Abrahams, had previously read out in the Commons the names of 29 people who have died.
Ken Butler, DR UK’s Welfare Rights and Policy Adviser DR UK, said Disabled people had their benefits cut and suffered "fear and anxiety" due to "poor and inaccurate medical assessments" carried out on behalf of the DWP by the private contractors Capita, the Independent Assessment Services (formerly called Atos) and Maximus.
For more information on the BBC investigation see Deaths of people on benefits prompt inquiry call available from bbc.co.uk.
See also the related DR UK news story Secretary of State: DWP has no legal duty to safeguard the wellbeing of vulnerable claimants.