The investigation began after Tauranga City Council became concerned about Cameron's designs, construction monitoring, and his behaviour and professionalism towards council staff and complained to Engineering New Zealand.
In 2018 Engineering New Zealand's Disciplinary Committee found the services Cameron provided between 2015 and 2016 did not meet the standard reasonably expected from a Chartered Professional Engineer.
In its finding, the committee said it had "grave concerns" about the thoroughness and accuracy of Cameron's work.
It said examples provided by the council showed "a concerning pattern of poor practice".
"While some examples may seem relatively minor, others are much more concerning. Taken together, they demonstrate an overwhelming lack of rigour and attention to quality practice that is of significant concern to us.
"The scale of Mr Cameron's misconduct, his apparent lack of insight into his actions and his unwillingness to change throughout this process deeply concerns us."
The key points of the council complaint included Cameron did not act with honesty, objectivity and integrity, behaved unprofessionally, including criticising council staff and provided engineering services that did not meet a reasonable standard.
The council also complained he signed and submitted producer statements without supplying sufficient supporting information and for building work that did not comply with building consent requirements.
A complaint that Cameron misrepresented work as being his own when it was carried out by another party was withdrawn by the council and the committee finding said the committee did not find Cameron's behaviour to be dishonest.
The other complaints were upheld.
The council complaint was illustrated by examples from 33 properties and statements from five engineers employed by or contracted to the council. In the finding, it is unclear if any of the 33 properties related to the Bella Vista development.
"[The council] submitted that the information it provided demonstrates a pattern of professional practice and behaviour by Mr Cameron that must not be permitted to continue," the finding said.
Some of the examples laid out in the finding include an instance where Cameron allowed building work to be constructed without consent. In another he asked a council staff member "should I design the house for a spaceship to land on the roof?" in a discussion about a retaining wall that differed from the original design.
On another occasion, a council consulting engineer raised concerns about designs for a deck balustrade. The engineer suggested redesigning the balustrade and told the committee investigating the complaint the design contained "fundamental" errors "going to the very core of structural analysis".
"They raise significant concerns with me about the standard of Mr Cameron's competence."
Asked about claims his designs were often inadequate, Cameron said many of his
designs were for routine work and standard designs were sufficient unless there was geotechnical input required. He believed the council needed more information than justified in many cases, the finding said.
Trevor Robertson, an expert adviser to the Investigating and Disciplinary Committees said, in his view, Cameron had been resistant to changes in the overall building consents landscape and unwilling to modify his practices.
Cameron acknowledged this in his submissions to the Disciplinary Committee.
"Robertson concluded that Mr Cameron 'appeared to resist complying with [the council]'s current requirements and therefore did not conform to the norms of the profession'. We agree with this advice," the finding said.
Cameron said at the hearing he did not consider the council's concerns were as serious as it was making out.
According to the finding, in complaints about unprofessional behaviour, Cameron said if the complaint related to "adopting an advocacy role in supporting clients against what at the time seemed to be over-the-top requirements, then he accepted that he may have at times pushed his client's positions".
"He reconfirmed this is no longer part of his practice and he now understands that his role is to be objective and not act as an advocate."
Cameron stated he has never in his "professional life knowingly acted dishonestly and have never provided knowingly wrong facts and have at all times attempted to be objective".
In its finding, the committee said it had "grave concerns" about the thoroughness and accuracy of Cameron's work.
It found Cameron had "exhibited a concerning pattern of poor and unacceptable practice over a long period of time".
It removed Cameron's registration for two years.
The two-year removal period ordered by the Disciplinary Committee has expired, meaning Cameron can re-apply for registration.
Cameron and his company The Engineer Limited were among parties prosecuted by Tauranga City Council over the Bella Vista development.
He and the company were found guilty of six charges relating to Building Act breaches, and in April were each fined $45,000 in total.
