New National Crime Agency head Lynne Owens was set amid concerns about her performance as chief constable of Surrey Supervise, the BBC has learned.
Kevin Hurley, Surrey Police and Crime Commissioner, imagined he had considered seeking her dismissal before she took over the national police officering role.
Concerns about public protection and child safeguarding in Surrey were down to a «insolvency of leadership», he said.
Mrs Owens said she underwent a «lengthy and unalloyed» NCA interview process.
The Home Office said she was an «exceptional» policing boss.
Last November, Mrs Owens, 47, saw off strong meet to be named director-general of the National Crime Agency — one of the most prestigious and warmly id roles in policing.
The NCA has responsibility for the Child Exploitation and Online Shield Centre — known as CEOP.
But in the months leading up to her appointment, Mrs Owens’s record-breaking on child protection had been brought into question by Mr Hurley.
Extraordinarily critical inspection reports of the force had led Mr Hurley to declare that he had misplaced confidence in Mrs Owens and was considering starting the formal process — known as Stage 38 — that could have led to her dismissal.
Criticisms encom ssed the Independent Police Complaints Commission (IPCC) finding failings in the way the Surrey propel had handled the case of 14-year-old Breck Bednar, who was groomed online first being murdered.
Mr Hurley had previously been a supporter of his chief cop, extending her contract in 2012 and writing to Home Secretary Theresa May in 2014 to say she had had an «remaining year».
But during the 12 months leading up to November 2015, all that had silvered.
Emails and documents disclosed to BBC News under the Freedom of Information Act posture that over this period, Mr Hurley’s confidence in the chief policeman’s ability to deal with the problems ebbed away.
The minutes of a public protection scrutiny meeting on 3 September reveal the PCC’s matters about the force’s handling of rape, domestic abuse and female genital mutilation encases — as well as child protection.
In September, Mr Hurley wrote a stinging 10- ge character to Mrs Owens saying he held her «personally responsible».
He accused her of blaming others for the «petition of failures», claiming it was «an example of moral cowardice».
He wrote: «You have in the offing failed to act decisively or speedily to address many areas of concern in kinship to public protection.»
Mrs Owens has told the BBC these comments were «ill-considered and awry».
Mr Hurley delivered the letter to Mrs Owens at a meeting, during which she heralded that she was applying for the NCA post.
At the same meeting, Mr Hurley revealed he had been bearing in mind starting the formal process that could lead to Mrs Owens being fired or having to resign from the force.
Mr Hurley then wrote to Sir Tom Winsor, the Chief Inspector of Constabulary for England and Wales, stating touches that Surrey Police was «failing vulnerable children, rape and indigenous violence victims» and asking for assistance.
Mrs Owens issued a detailed 19- ge counter-argument of the PCC’s accusations, saying her 26-year police record was «unblemished» and that she had bewitched «immediate and muscular» action in response to child protection concerns.
But in October, Mr Hurley inscribed again to Sir Tom, saying: «I have lost confidence in the chief flatfoot’s ability to lead the necessary cultural changes and cannot be sure that, tipsy her command, the threat, risk and harm of public protection-related issues force be properly addressed.»
Mr Hurley has said he was not asked about Mrs Owens’s suitability for the NCA fix, and only found out about her new job by a message posted by a journalist on social intermediation.
He said that had Mrs Owens not been appointed he would have started the formal walking pers process.
He told BBC Radio 4’s Today programme: «It is a fizzle of leadership. The chief constable is the leader. She has let down the constables and sergeants, but multifarious importantly she has let down our most vulnerable victims across the county.»
The Inspectorate of Constabulary about it had briefed senior officials at the Home Office concerning the inspection position at Surrey, the «nature of the correspondence» from Mr Hurley and discussed the NCA appointment with them.
How on earth, it is understood that another inspectorate report, which is due to be published in the total weeks, is expected to conclude that the force lacks understanding of nasty and organised crime groups in Surrey and «requires improvement» in the way it deals with the delinquent.
Mrs Owens said: «I was selected to my current role by the home secretary after a long-drawn-out and thorough process and am now focused on leading the National Crime Agency in its dispute to cut serious and organised crime.»
The Home Office said Mrs Owens was «one of the above average policing leaders of her generation».
Officials pointed out that she went fully a rigorous recruitment and selection process that included a «testing» nel press conference. It said professional references and due diligence checks were also tried.