Otago Rugby Football Union (ORFU) board members Laurie Mains and Wayne Graham together want more than $1 million in damages from Dunedin Mayor Dave Cull for alleged defamatory comments made during a radio interview.

Court documents show Graham and Mains, ORFU chairman and deputy chairman respectively, are each seeking $500,000 in "general damages" from Mr Cull, the Otago Daily Times reports.

The statement of claim also shows the pair want unspecified "special damages" for loss of business income as a result of damage to their business reputations, plus interest and costs.

It was reported last month that Mains and Graham had threatened Mr Cull with legal action if he did not apologise for comments he made during a Radio New Zealand interview.

The interview, in March, related to the council wiping $480,000 of debt owed by the union to the council and the council-owned Dunedin Venues Management Ltd.

The council also provided $500,000 worth of loans.

The statement of claim says Graham and Mains wrote to Mr Cull the following day requesting a retraction.

They later offered to have a judge determine the content and presentation of the retraction, but no agreement was reached.

Mr Cull subsequently wrote two proposed apology letters addressed to board members. However, the document says comments in the letters written by Mr Cull were an aggravation of damages and weren't a retraction.

The ORFU was saved from liquidation in March after chalking up debts of $2.35 million.

At the time Mr Cull defended the council's decision to help rescue the union, saying if the union had gone into liquidation none of the money owed could be recovered.