National leader John Key has revealed he was interviewed by the Serious Fraud Office, and he has predicted the government will use this as their next attack against him.
Key said he was interviewed about the Equiticorp scandal of the 1980s, when he was working at Elder's Finance.
The interview related to Elders' involvement in Equiticorp's sale of New Zealand steel in 1987 and the payment of a multi-million dollar fee to the Equiticorp boss.
Key says he has nothing to hide.
On Thursday Labour tried to link Key to a leaky home development.
In parliament Labour accused Key of being a director in an Auckland property firm that is attempting to go into liquidation to avoid leaky building costs.
The architects involved in the construction of the building were the Leschke Group, which has gone into liquidation.
One of the directors of that company was Colin Leuschke, who has a business relationship with Key.
Key is adamant he has no involvement in a leaky building issue his political opponents are trying to tar him with. He says he is a director in the company identified, but it is not subject to any leaky building claims.
Political commentators say attacking politicians for their business interests rarely works with the public.
Political columnist for the National Business Review, Ben Thomas, says there is a similar example from the Labour benches.
Thomas says it wasn't that long ago that David Parker was being hauled over the coals for very small technicalities in his business dealings.
Parker had to resign as Attorney General as a result, but Thomas says the scandal didn't do him too much harm. He says there is a high likelihood the tactic will backfire for Labour.
