The Weekend Herald has chosen not to name the man or his colleagues to protect the privacy of those involved.
The co-workers said within three months of the manager being appointed, there were significant changes in the man's appearance and demeanour.
"He looked terrible," one colleague said. "He'd lost a lot of weight, he looked ill. And there was other stuff, he wasn't sleeping, he was totally flat when you talked to him. There was nothing there."
Once a keen athlete, the man stopped exercising. He began pulling and twirling his hair, sometimes pulling it out. One woman told the Weekend Herald how others mocked the behaviour behind his back, and how distressed he was when he caught them.
Three co-workers said the man told them he was unhappy with his manager. The manager spoke over him or ignored him, and shouted at him, they said.
He told them he felt stressed, helpless and depressed. All the while, he was working 16-hour days. He said he had tried to raise it with the manager, with no success.
One colleague said the man also met with Human Resources to seek support and guidance.
"[They told him] it appeared that this was just what was expected of managers and he more or less just had to suck it up."
Mid-year, two colleagues said he told them he had attempted suicide. As a result, he was hospitalised. When he returned to work he tried, unsuccessfully, to raise his concerns with his manager, again.
On July 16, the man emailed a formal complaint about his manager to Housing New Zealand.
"Over the past six months I have been subjected to a campaign of bullying and intimidation by this manager, and despite numberous (sic) attempts to address this issue nothing has been resolved, indeed I have not been offered or received any support from the organisation in relation to this matter," he said.
The man said his mental health had suffered, and the department had failed him. He wanted a formal investigation, and a reply within five working days, or he would resign.
It is unknown if he got a reply. Ten days later, he was dead.
On the day of the funeral another staff member emailed the chief executive and the board, warning of a feeling of disharmony, and of "unacceptable pressure" placed on some people.
"The current leadership of the group shows no empathy for the wellbeing of the team and has unrealistic expectations of performance and provides only negative feedback, fails to communicate appropriately, and is not openly approachable or open to free dialogue," the email said.
Following that, another employee claimed she also raised the alleged bullying with the chief executive. He has since denied that disclosure occurred.
The staff members claimed that the behaviour of the manager in question was tolerated because the manager got results. They reported the issue to advocacy group CultureSafe NZ, seeking help.
CultureSafe director Allan Halse said he had no doubt WorkSafe should be investigating what he called a health and safety "failure".
Frazer Barton, a health and safety lawyer and partner at Anderson Lloyd, said the new laws created a clear obligation to report matters of mental health.
"It's not as simple as someone falling off a ladder, but as a general principle if there is harm in the workplace and there's an allegation it needs to be notified to WorkSafe," he said.
Housing New Zealand said the bullying allegations were taken very seriously and "thoroughly and independently" investigated after the man's death.
It could not give further details of the case because it was under investigation by the Coroner.
"Housing New Zealand takes the wellbeing of its staff very seriously and has been working on initiatives that preceded the Coronial process, focusing on mental health and wellness in the workplace," it said.
WHERE TO GET HELP:
If you are worried about your or someone else's mental health, the best place to get help is your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call police immediately on 111.
OR IF YOU NEED TO TALK TO SOMEONE ELSE:
• LIFELINE: 0800 543 354 (available 24/7)
• SUICIDE CRISIS HELPLINE: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• YOUTHLINE: 0800 376 633
• NEED TO TALK? Free call or text 1737 (available 24/7)
• KIDSLINE: 0800 543 754 (available 24/7)
• WHATSUP: 0800 942 8787 (1pm to 11pm)
• DEPRESSION HELPLINE: 0800 111 757