Riot Foods was placed in voluntary administration in early February after damage to a manufacturing plant left it desperate for cash.
Administrators Iain McLennan and Peri Finnigan of McDonald Vague have been working on sale options for the owner of the CleanPaleo and Poppy & Olive brands.
McLennan told the Herald the administrators did not agree with Kamins' claims and were seeking legal advice on the contents of the letter and attachments.
"Ryan has no role with the company. We are very concerned that after his resignation from the companies, Ryan has undertaken an unauthorised release of confidential company emails, in a selective way. "We are reviewing our legal options in the first instance against Ryan in that regard, and those may include any party that further distributes the emails, or their contents.
"The administrators and company directors are of the firm view that the emails and notes do not support Ryan's allegations and conclusions.
"As Ryan has stated, it is his opinion. Ryan has acknowledged he has limited legal knowledge."
Riot was founded by Kamins, former Black Cap Mitchell McClenaghan and television personality Art Green.
Early last year it raised $1 million in equity through crowdfunding platform PledgeMe from 157 investors and planned to raise $1m more the same way a year later. But in October the company revealed it was facing significant challenges, saying damage to its Ascot Rd facility caused it to miss its production date.
The receivership of major client NZ Deli was also an issue.
Kamins then told Riot shareholders in a letter that it needed to raise $1m in two weeks, or sell the business. He would later resign as chief executive and director in November, citing alcohol addiction.
According to the administrator's first report, Riot Foods owed a combined $6m to shareholders and creditors, with "just under" $1m owed to creditors.
The Herald has approached Ryan Kamins for comment.