Sandra Haynes-Kirkbright claimed 'every rule in the book' was broken at New Cross to improve mortality rates. Her allegations and subsequent treatment sparked an investigation.
And that probe has overrun by nine months because of its complexity, the Express & Star can reveal.
The NHS Trust Development Authority (TDA) inquiry was due to last three months, beginning last March, but is still ongoing almost a year later.
New Cross chief executive David Loughton initially welcomed the investigation insisting that Royal Wolverhampton NHS Trust had nothing to hide. Investigators have been and gone but no report has materialised yet.
Mrs Haynes-Kirkbright was last year warned she faced the sack but is still on suspension and still being paid.
She claimed she had been head-hunted to 'fix' mortality rates.
The whisteblower alleged she was suspended after she refused to take part in a cover-up. However Mr Loughton vehemently denied the claims and called them an 'outrageous slur'.
Mrs Haynes-Kirkbright was suspended in July 2012 because of allegations made against her by colleagues of bullying, harassment, persistent swearing and unprofessional behaviour.
Now, almost three years later, Mrs Haynes-Kirkbright is still being paid by the trust but is not currently at work.
The whistleblowing investigation at New Cross was commissioned by the TDA and undertaken by independent consultants Verita.
Royal Wolverhampton NHS Trust spokesman Phil Edmeades said: "The Royal Wolverhampton Trust has not received a copy of the report commissioned by the TDA.
"We have engaged fully with the investigation and inquiries. Sandra Haynes Kirkbright is still employed by the trust."
Mrs Haynes-Kirkbright declined to comment on her suspension or the TDA investigation.
A health coder who is originally from Texas and now lives in Stafford, she claimed conditions at Wolverhampton were as bad or worse as those at the now dissolved Mid Staffordshire NHS Foundation Trust.
Her job involved recording details of the care received. The role did not require her to have medical qualifications.
An NHS TDA spokesperson said: "An independent investigation was commissioned last year for Verita to investigate a complex whistleblowing case at Royal Wolverhampton and ensure a robust and thorough approach.
"The review is still in progress and the findings will be published when this work has fully concluded."
Last week Sir Robert Francis QC -who led two inquiries into failings at Stafford Hospital - made a string of proposals aimed at giving whistleblowers more courage and confidence to speak up over poor care without fear of damaging their careers.