Rob Alloway says he has resigned as an Allied Farmers director because a of stoush with the board over what he says was a conflict of interest involving another director in the Hanover deal.
He was heavily involved in Allied Farmers purchase of Hanover's loan book for $400 million in December 2009.
The buyout has plagued the company, whose share price has plunged 95% following asset writedowns, the receivership of its own finance arm, huge losses and cash problems.
Mr Alloway, who resigned suddenly on Thursday, says he feels there was inadequate disclosure of a fee paid by Hanover to the company McDouall Stuart, which is run by fellow director Andrew McDouall.
He says the board has not been supportive his efforts to get more information about the transaction.
But Andrew McDouall, says the involvement of McDouall Stuart in the transaction was disclosed to the Allied Farmers board from the outset.
Mr McDouall says as a director of Allied Farmers he made a disclosure of interest at each board meeting thereafter.
Mr Alloway will continue as chief executive of Allied Farmers until his contract expires at the end of June.