Environment Canterbury chairperson Peter Scott has resigned.
His departure as regional council chair follows revelations his council-provided car exceeded the speed limit 678 times since January, with a top speed of 157km/h.
A speeding report from his council-provided car showed it exceeded the posted speed limit by 50km/h on five occasions, including travelling at 105km/h through a 50km/h zone on 10 May.
The council's policy indicated anything in excess of 15km/h above the speed limit was considered excessive and the report showed there were 326 instances in which Scott's car travelled at excessive speeds this year.
The council said there was no code of conduct or disciplinary procedure underway, and no further action was needed from the chief executive.
The Toyota Highlander had now been returned to Environment Canterbury.
In July, Scott also received a formal warning following an independent investigation into his own claims he was "operating illegally" on his South Canterbury farm.
Council chief executive Stefanie Rixecker ordered the investigation in May after Scott revealed in a NewstalkZB interview he was not operating with formal resource consents because of processing delays.
"Following recent publicity about my personal behaviour it has become increasingly apparent that the focus on me is a distraction from the work of the Canterbury Regional Council," Scott said, in a statement.
"Although this publicity has not been directly related to my work as Chairman, I recognise the damage it is doing to this organisation, and I have decided to step down as chair, effective tomorrow.
"I acknowledge I've made mistakes from a personal perspective, and these are for me to learn from. By stepping down as chair, I expect the focus to shift from me to the work we need to deliver for the environment and the people of Waitaha."
Scott said he was proud to have led the council through "important and challenging work" since 2022's local elections.
He would remain on the council in his role as councillor for South Canterbury-Ōtuhituhi.
"I make no secret of my ambitions for the region and as chair I have advocated strongly on Canterbury's behalf - something I will continue to do.
"As a council and an organisation we've achieved a lot but there is more work to be done."
Deputy chair Craig Pauling would step in as acting chair until a new chair was appointed for the remainder of the term at the council's 23 October meeting.
Commissioners were previously installed at the council at 2010 and remained in place in some form until 2019.
Scott was first elected as a councillor in 2016 during a mixed governance period and re-elected in 2019 and 2022.