Prof Susan Deacon has resigned as chair of the Scottish Police Authority (SPA).
In her resignation letter, she said she believed “accountability arrangements for policing in Scotland are fundamentally flawed”.
Ms Deacon was Labour MSP for Edinburgh East and Musselburgh from 1999 to 2007 and served as Scottish health minister.
When she was appointed in 2017, then justice secretary Michael Matheson said she would “bring a fresh perspective to the governance of Scottish policing”.
Writing to Mr Matheson’s successor, Humza Yousaf, Ms Deacon said: “I have, as you have frequently acknowledged, worked tirelessly to try and ensure that the SPA operates effectively, and that public confidence and trust in policing is maintained.
“I have also made every effort to attempt to make the existing statutory framework operate as I believe it was intended.
“In truth, however, I have increasingly become convinced that the governance and accountability arrangements for policing in Scotland are fundamentally flawed, in structure, culture and practice, and I conclude that there is little more I can do to make these arrangements work effectively.”
SPA Vice Chair David Crichton will take over leadership of the authority’s board on an interim basis.
He paid tribute to the work Prof Deacon had carried out but insisted the system for police oversight was “sound”.
Mr Crichton said Prof Deacon had taken up the role during a period of “considerable instability in the police service”.
He added: “We believe that the system of governance and accountability for policing in Scotland that was envisaged by the founding legislation is a sound one and can work effectively.”
“While we respect this personal decision of the chair, our collective focus will be on working together with our dedicated staff team to build on recent progress, deliver the actions and improvements already identified, and redouble the SPA’s focus on the issues of greatest importance to policing and the public.”