The worker who lodged a complaint against Andrew Bayly said the minister's behaviour toward him did not live up to the "etiquette" which he had upheld during his five years in the Defence Force, the unredacted letter shows.
Bayly's office on Friday released a redacted version of the complaint in which the worker stated that Bayly repeatedly called him a "loser" and told him to "f*** off" during a ministerial visit to his place of employment earlier this month.
The minister said he did not recall swearing at the worker but apologised "unreservedly" for his behaviour which he said was meant to be "light-hearted".
RNZ has since obtained unredacted copies of the correspondence, confirming the incident took place at a Spy Valley Wines facility in Marlborough on 3 October.
Bayly's social media shows he made a "final stop" at the winery that day during a ministerial visit to the region. The winery did not respond to RNZ's requests for comment.
In his letter, the complainant said Bayly's actions were unacceptable and should not be tolerated in any professional setting.
"I did not dedicate five years of my life to the NZDF only to be belittled by an ambassador of the very government I served," he wrote.
"I have been part of the repatriation of fallen soldiers being returned from South Korea, I have been apart of, [sic] and lead, [sic] cultural ceremonies for the royal family's visits to New Zealand, and for various foreign dignitaries - all of which require a form of etiquette severely lacking in Andrew Bayly."
The complainant has not responded to RNZ's requests for comment.
As earlier reported, the worker also claimed that Bayly's behaviour suggested "he had been drinking prior to arrival", a point Bayly denies.
On Tuesday, Labour MPs interrogated Bayly during Parliament's Question Time over whether he had been drinking at any time during the incident.
Bayly told the House he had no alcohol at all before any of his interactions with the complainant but did have a small wine tasting at the end of day.
Sign up for Ngā Pitopito Kōrero, a daily newsletter curated by our editors and delivered straight to your inbox every weekday.