Welsh health minister Edwina Hart has continued to deny withholding critical findings about the NHS.
It followed the leak of a 75-page document by management consultants McKinsey which opposition AMs said reveals failings in the health service.
Lib Dem leader Kirsty Williams has accused Mrs Hart of misleading the Assembly by failing to publish the document, marked “restricted - policy” and “draft”, when asked.
Under the heading “shortcomings we have heard”, the document says that strategic objectives are “too numerous and not prioritised, so none or the wrong ones are implemented”.
It adds that “implementation lacks accountability” and that “initiatives are financially unaffordable”.
Mrs Hart came under pressure about the disclosure during health questions in the Senedd.
But she said the paper was a “discussion document” and that “there is no McKinsey report”.
She said: “There are no secrets in the NHS. There are always leaks in the NHS and I believe that the document that you are referring to has been knocking around with chief executives for a considerable length of time and if it’s with chief executives it will be with other senior staff in the LHB (local health board).
“Some of us, of course, have had experience of life elsewhere in the development of policy agenda both in the public and private sectors and we know that there are always discussion documents and always scenarios.
“I am afraid there’s no great news story in any of this, however you may huff or puff.”
She said she had an “excellent working relationship” with her department and the NHS.
“Openness and transparency is what I have always strived to do as a minister,” she added.
Mrs Williams asked first minister Carwyn Jones to investigate her claim that Mrs Hart misled the Assembly in breach of the ministerial code of conduct.
In a letter to the first minister, she said: “Call it what you will, it is now clear that your minister has suppressed a document of critical importance to the NHS in Wales in order to cover up the criticism of her own leadership of her department.”
For the Conservatives, shadow health minister Andrew RT Davies accused Mrs Hart of secrecy.
“How can we allow a health minister to tell AMs a critical report does not exist, when it so obviously does?” he said.