OTTAWA — Elections Canada is refusing to say whether allegations that the Conservative party altered invoices for campaign expenses will result in charges related to the so-called "in-and-out" election-financing scheme.

After four former Conservative party officials were charged with Elections Act violations last month, opposition MPs have repeatedly accused the Conservative party of "forging" key documents in 2006 election returns.

The allegations, which first surfaced in 2008, refer to invoices used by the Conservatives to back up radio- and TV-advertising expense claims submitted by their candidates.

Conservative party spokesman Fred DeLorey calls the allegations "absurd" and says the invoice issue has been dealt with and resolved.

"There was no falsifying of invoices," he said in an email.

As DeLorey noted, there are no specific allegations of document fraud in the list of charges laid against the four party officials last month. "Elections Canada isn't even saying that anymore. They dropped it," he said.

But the office of the Director of Public Prosecutions, which recommended laying the charges, says it was never asked to consider forgery charges because the matter would fall outside the Elections Act.

"We have no other referrals on this matter from the Commissioner of Canada Elections," said DPP spokesman Dan Brien. "That doesn't necessarily answer the question, which I can't answer because it doesn't relate to a matter we would prosecute."

Forgery and making a false document are offences under the Criminal Code and would not be prosecuted by Commissioner of Elections William Corbett, who is responsible for enforcing the elections law.

If warranted, Corbett could refer evidence of illegal activity that falls outside the Elections Act to another agency — likely the RCMP, in the case of forgery — but there is no indication he has done that with the invoices.

Elections Canada, which handles media calls on Corbett's behalf, declined to comment on the matter, as it has done throughout the five-year legal battle.

Two of the charges laid last month allege the party and its fundraising arm, the Conservative Fund Canada, submitted an election return they "knew or ought reasonably to have known contained a materially false or misleading statement" involving the recording of expenses.

It is unknown, however, if this refers to the altered invoices.

Brien said he didn't know and couldn't comment if he did, as he cannot discuss what evidence will be presented in court.

The invoices at the heart of the in-and-out case were created by an advertising agency, Retail Media. They listed radio- and TV-airtime purchases the agency made in the party's $1.3-million ad campaign during the 2006 election.

Elections Canada contends that the invoices were part of a scheme the Tories used to skate around its $18.3-million spending limit. The party transferred money to pay for ads in and out of some of its candidates accounts, Elections Canada claims, and the invoices were used to back up the expense claims.

An Elections Canada affidavit filed in 2008 said a Retail Media official was shown a copy of an invoice for $39,999.91 for one of the campaigns in the Toronto area. The official "stated the invoice must have been altered or created because it did not appear to conform to the appearance of invoices sent by Retail Media to the Conservative party."