New Zealand Post board chairwoman Jane Taylor has resigned two years into a three-year-term.
"I believe the company is in great shape, with a strong strategy to be the best delivery business for New Zealand. I'm very proud of what the company has achieved in the last few years," Taylor said in a statement issued by NZ Post.
NZ Post chief executive David Walsh thanked Taylor for her "substantial contribution to the strategy and direction".
"She's helped guide us to an extremely strong place, locking in the strategy that everyone is now working so hard to deliver on," he said in a statement.
"Jane has decided to resign from the NZ Post board, and I have accepted her resignation," Finance Minister Grant Robertson said.
"We'd like to thank Jane for her significant work in setting up NZ Post's strategy, and guiding the organisation through a significant period of change," he said.
Robertson later told reporters Taylor, who was appointed by the previous National government in 2016, had resigned over matters internal to the New Zealand Post board. He did not elaborate.
"Ms Taylor was appointed for a three-year term. Clearly it's earlier than that. But those really are matters internal to the Post board," he said.
Robertson said a report he and Associate SOE Minister Shane Jones had received from Treasury related to those matters.
Jones told reporters there had been recent press coverage over issues around Taylor and her relationship with the board and she had written a letter of resignation.
"That's really where the ball has bounced."
Stuff reported two weeks ago that Robertson was aware of Taylor's intention to resign following rumours of unhappiness on the NZ Post board.
Taylor, a professional director and a trained barrister, resigned two years to the day she took over as chair of the Post from Sir Michael Cullen, after being appointed to the board in August 2016.
According to her NZ Post profile, Taylor is chairwoman of Landcare Research and Predator Free 2050, deputy chairwoman of Radio New Zealand and a director of Silver Fern Farms, Kiwibank and OTPP New Zealand Forest Investments.
Robertson said she would no longer be on the Kiwibank board given her resignation from the NZ Post board.
Current NZ Post board deputy chairwoman Jackie Lloyd has been appointed acting chairwoman of the board.