Smith said that by signing such a contract, the NZ First MPs had breached Standing Orders by failing to declare a financial interest in the Electoral (Integrity) Amendment Bill because it would relieve them of a potential liability.
Mallard wrote back saying that because none of the MPs had signed the contract, there was no breach.
Asked why he said on August 16 that all MPs had signed, Peters said that on later examination, he had discovered that none had.
"That was my memory. It was a constitutional change made some considerable time ago."
Peters said he wouldn't make them sign it now because it was obsolete.
"It was only a holding position until such time as a bill like this came along, and it has."
Peters was referring to the Electoral (Integrity) Amendment Bill, also known as the waka-jumping bill, which is expected to pass its third reading with the support of the Green Party.
The bill, which ensures Parliament's proportionality in the event that an MP leaves or is ejected from a party, is part of the Labour-NZ First coalition agreement.
Smith said Peters had told the Speaker that no NZ First MP had signed it to avoid a Privileges Committee hearing.
"NZ First MPs put themselves in the position of either breaching their own party rules or Parliament's rules. I suspect the MPs have cynically decided to deny the existence of the contracts because breaking Parliament's rules would result in a damaging Privileges Committee hearing and deferral of the Waka Hopping Bill whereas nothing will happen from them breaking their own party's rules," Smith said in a statement.
Meanwhile, Peters has defended the cost and location of two fund-raising dinners in October and November.
The $350-a-head dinner with Peters and the NZ First caucus will be held at the Auckland and Wellington offices of law firm Russell McVeagh.
Russell McVeagh yesterday announced it had appointed Jo Avenell as its new chief executive after accusations of sexual harassment and drunken behaviour rocked the company this year.
Peters said $350 was not a large sum compared with what National had been known to charge.
"$350 is not a cash for access matter."
He called Russell McVeagh a "reformed law firm".
"That's been made obvious by the new management," he said.