Conservative MP Dean Del Mastro answered only one question Thursday about a report that Elections Canada is looking into his 2008 campaign spending, leaving many MPs unsatisfied.

A report by the Ottawa Citizen and Postmedia says Elections Canada is investigating Del Mastro's spending in the 2008 election, where he won the seat in Peterborough, Ont.

Del Mastro says the election agency hasn't contacted him about an investigation and that he didn't spend more than his campaign limit, an offence with a maximum penalty of $5,000 or up to five years in prison.

No charges have been filed and the allegations have not been tested in court. Elections Canada refuses to confirm whether they are investigating, as is their policy.

Opposition MPs said they aren't getting any answers from Del Mastro.

"The answers we got today were a complete mystery to me. He didn’t indicate for a moment that he even understood the nature of the charges or the nature of the investigation that was underway. I thought it was a pretty extraordinary performance," interim Liberal Leader Bob Rae said.

Mystery cheque

Documents filed in small claims court in Ottawa suggest Del Mastro spent $21,000 of his own money on services provided by Holinshed Research Group, a company that he says did work for him as an MP and as a candidate, which are paid out of separate budgets. The company also did work for his riding association, he told Evan Solomon, host of CBC News Network's Power & Politics,  on Wednesday.

Federal election candidates are allowed to spend only $2,100 of their own money on their campaigns, with a penalty of up to $5,000 or five years in jail for spending more than the limit.

Del Mastro says any money he spent on his campaign was reimbursed by the campaign or by the riding association. Records provided on the Elections Canada website show no reimbursement for the $21,000 to him or his wife, whose name is also on the joint chequing account.

There was no repayment to Del Mastro from the riding association either, records show.

Del Mastro's election return shows his campaign spent nearly the entire amount allowed under federal election laws — $91,770.80 with a total limit of $92,566.79. Another $21,000 would have broken campaign spending laws, which have penalties of up to $5,000 or five years in prison.

Speaking to CBC News after his Wednesday appearance on Power & Politics, Del Mastro said he absolutely did not overspend in his campaign.

"All I can say is all of the expenses related to the campaign — all of them — have been fully accounted for and those statements have been fully audited and accepted by Elections Canada," he said.

It's not clear what the $21,000 cheque, dated Aug. 18, 2008, was for.

A document provided in the civil suit suggests Del Mastro's campaign manager, John McNutt, signed off on an invoice from Holinshed for that amount on Sept. 15, 2008. The invoice says it covered 630 hours of voter ID phone calls, as well as get-out-the-vote live calls on election day.

McNutt did not respond to a request for comment.

Small claims suit against Del Mastro dismissed

The investigation seems to stem from a lawsuit, which was dismissed as abandoned a year ago, court documents show. The suit was launched by Frank Hall, a former Reform Party staffer who started Holinshed.

The company's website and phone number no longer work.

In 2009, Holinshed got a $125,000 federal grant under the Canada Economic Action Plan stimulus spending to develop their GeoVote system.

NDP MP Charlie Angus seized on that in question period.

"So, who signed off on this expenditure and when? And will they show us the GeoVote application that Canadian taxpayers paid for? Where is it?"

Liberal MP Scott Andrews, the party's critic for ethics issues, called Del Mastro the right hand of Prime Minister Stephen Harper, and said he has to give up that role. He should also resign his position on the House ethics committee until the investigation is over, Andrews said in a statement.

"Mr. Del Mastro's role has been to breathlessly defend the government against serious electoral fraud allegations for months.... He cannot continue to answer for this government when he has these allegations of possible misconduct looming over his head."

Del Mastro has been the party's lead defender throughout the robocalls scandal involving misleading live and automated calls that directed voters to the wrong polling stations.

Del Mastro said Andrews has served on committee with him long enough to "know a couple of things about me."

"One is I serve with integrity and conviction, Mr. Speaker, and while that member and I haven't always agreed, he does know those qualities about me."

Del Mastro said the financial statements provided to Elections Canada in 2008 accurately reflect all expenditures incurred by both his campaign and his riding association.

"Anything I paid on their behalf, was refunded to me. I stand by those."

Conservative MP Pierre Poilievre took the remainder of the opposition questions about Del Mastro's campaign finances.