A former NHS whistleblower has warned the 1000 confidentiality clauses preventing former public sector employees from speaking out about dangerous conditions at work, are only "the tip of the iceberg".
NHS whistleblower Gary Walker told Daybreak despite the Public Accounts Committee's best efforts, they "could not get the answers" on how many people hd signed a gagging order from the Treasury.
"Nobody in Government departments knew how much was being spent, so they asked the National Audit Office to look - they couldn't find out because the councils and other public bodies could not tell them.
Public bodies "reward failure" so they can "avoid attracting unwelcome publicity" by making would-be whistleblowers and failing chief executives sign gagging orders, the head of a group of influential MPs said.
Public Accounts Committee (PAC) chair Margaret Hodge said whistleblowers were "vital" if tragedies like Mid Staffordshire and Baby P were to be avoided.
It is vital that people feel free to speak out to help prevent terrible tragedies or even deaths, and protecting the reputation of an organisation, such as the NHS, at the expense of public safety is unacceptable.
A confidentiality clause in a compromise agreement is not meant to prevent legitimate whistle-blowing - but people who have been offered, or accepted compromise agreements have clearly felt gagged.
The Public Accounts Committees (PAC) said confidentiality clauses in compromise agreements were being used to pay off employees who wanted to highlight concerns.
Inadequate monitoring by the Government meant it was now impossible to know how many of these were in use or whether they should have been signed off in the first place.
Investigations by the National Audit Office (NAO) last year found the Treasury had signed off more than 1,000 special severance payments linked to compromise agreements for departing staff since March 2010.
Over £28.4 million was paid out - but the true figure will be much higher as this does not include local government, the police, the BBC, or private contractors.