The Green Party has suspended low-ranking candidate David Hay for attacking the party's leaders and releasing internal documents.
The Greens launched an investigation in November after Mr Hay challenged for the leadership of the party.
A panel found that he had breached the party's code of conduct and recommended a ``cooling down'' period of one year.
A report by the panel said Mr Hay had admitted breaching party rules by releasing internal documents which related to the process of choosing candidates.
He had also attacked co-leaders Russel Norman and Metiria Turei in press statements.