She said another incident was when her son felt punished after foregoing normal protocol to save a man's life. Mary said her son was put on supervision for six months, during which, his family say, he felt belittled and bullied by management.
"I could see he was losing confidence in himself," said Mary. "He became distant," said Jeremy Avis' father, Jim.
"It's bullying that erodes people's confidence. It just does. It kills them, it destroys them," Mary told RNZ.
The other nurse who killed himself in 2013 left behind a note to his colleagues on the ward where he worked at Tauranga Hospital: "I hope you are all happy now that I'm gone. I look forward to meeting you all again in Hell!"
A number of other staff had since come forward saying they felt bullied, ignored and in some cases had been sacked after speaking out.
Bay of Plenty DHB chief executive Helen Mason told RNZ the suicides were devastating. The board was committed to an anti-bullying culture and took allegations of inappropriate behaviour seriously.
She said the DHB found "significant and material differences" in the accounts given by the staff, but had ongoing work programmes to tackle bullying as part of continuous quality improvement.
"The DHB's commitment to tackling inappropriate workplace behaviour has been demonstrated through the 'Creating our Culture' programme of work over the last 18 months. 'Creating our Culture' includes a workstream specifically focused on 'inappropriate behaviours' and is one of the DHB's four key strategic priorities.
"We have received a lot of very positive feedback about the programme, from staff, our employee union partners, and our patients, and are proud of what it has achieved to date. It is impossible to work at the BOPDHB without being aware of how much the values and expected behaviours highlighted by Creating our Culture matter to us all."
RNZ revealed between April 2017 and March 2018, the DHB recorded 13 formal bullying complaints: three were unsubstantiated; three were substantiated; and seven are still under investigation.
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