The correspondence suggested the broadcaster's reputation had been damaged by the sponsors' boycott of RadioLive and also requested company policy and guidelines which led to the decision to suspend advertising.
A number of sponsors such as Yellow, Telecom and ANZ pulled advertising from the radio station after a social media backlash provoked by an interview about the Roast Busters by Tamihere and Willie Jackson with a caller who identified herself as "Amy".
At one stage during the interview, Tamihere asked how old she was when she lost her virginity. "How free and easy are you kids these days out there?" he asked. "You now, you were, like, 14, yeah?"
Both hosts agreed to stand down while the company dealt with the fallout. Jackson was later reinstated but Tamihere's contract was not renewed.
The MediaWorks' radio standards committee ruled the interview did not breach broadcasting standards and Tamihere has now filed a $620,000 lawsuit against the company that alleges breach of contract and defamation.
The Herald can reveal that Tamihere's lawyers sent letters to some of the corporate sponsors who pulled their advertising from RadioLive asking for copies of the policy and guidelines that led to the decision.
A spokesman for Telecom said the letter from Tamihere's lawyers "suggested that, among other things, Telecom's decision to remove advertising somehow harmed Mr Tamihere's reputation".
"In our response we completely rejected this assertion," said the spokesman. "We remain comfortable with the decision made at the time to temporarily withdraw our advertising. The decision was made after listening to customer and community views expressed over the handling of the Roast Buster issue. We received strong support from our customers for making this call."
The spokesman said Telecom respected the right to freedom of speech but "that right also extends to the choice of advertisers as to where and when they advertise".
Vodafone and Countdown confirmed they had received legal letters but declined to comment on the contents or their response, while ANZ and the Briscoe Group said they did not get letters. Other sponsors who pulled advertising did not respond in time for publication.
Tamihere said he took "great umbrage" at companies "using their chequebooks to determine the moral compass of this country".
The notion that major firms could use their financial clout to determine the editorial policy of news organisations was disturbing. "I find that unacceptable. That's why I've done it and I'm not finished with them yet."
