"He sustained serious head injuries, but there were no witnesses, and there was no CCTV or the like.
"So we really don't know what happened."
Mr Nind said the two-week delay in releasing information on the serious injury had been out of respect for the man's family.
"We were working with the family, and that was their wishes, so we stood by those.
"The family is distraught, as you could imagine.
"We're giving them as much support as we can, as they grieve the loss of their much-loved husband, father, and brother.
"This has come as a shock to our small, tight-knit team, particularly those who worked alongside the man and immediately helped after the incident.
"All round. It's tough."
Counselling is available to CentrePort workers who request it.
Mr Nind said the company was co-operating with health and safety inspectors from WorkSafe.
A WorkSafe representative confirmed an investigation is under way.
"Our condolences go to the family and colleagues.
"WorkSafe NZ is investigating and, therefore, we are unable to provide any further information now that an investigation is under way."
The Maritime Union said the incident was a sad loss of a friend, colleague, and comrade.
It's expressed deepest sympathies to the late member's family and loved ones.
"Yet another worker has died on the job in New Zealand, and that's not good enough," National Secretary Joe Fleetwood said.
"Nobody should lose their life while trying to earn a living."
Assistant Wellington Branch Secretary John Whiting said it was a tragic instance where the worst had happened.
"The waterfront industry by its very nature is a high-hazard workplace.
"Safe work practices must be rigorously implemented and enforced, both by management and by organised workers ourselves."
