Prime Minister Stephen Harper's parliamentary secretary, Dean Del Mastro, who is under investigation by Elections Canada, says recent media reports alleging his family was involved in a donation reimbursement scheme are baseless.

The reports have alleged that a company owned by Del Mastro's cousin, David Del Mastro, reimbursed its employees for contributions to his campaign. Under the Elections Act, it is illegal to conceal the source of a political contribution.

Speaking at an event in his riding of Peterborough, Ont., on Wednesday, Del Mastro said the allegations have taken a toll on his family, which runs a business in this community northeast of Toronto.

"(The business) has my father's name on it — I take it very seriously," he said.

"So when my name is thrown around in the media, especially with allegations that have no process, you have to understand — this is a very unfair thing."

Elections Canada alleges that Del Mastro, who normally defends the Conservatives against accusations of dirty electoral tricks, exceeded his spending limit during the 2008 campaign and then tried to cover it up.

The matter revolves around a contract for polling and research.

In court documents, Elections Canada claims Del Mastro paid Holinshed Research Group $21,000 out of his personal bank account. But the Peterborough MP's campaign return shows only $1,575 was paid to the company.

The agency alleges Del Mastro "took steps to hide the true nature of the transaction by paying the $21,000 election expense from his personal bank account ... and obtained a false invoice from Holinshed in December 2008 ... which was never paid to Holinshed."

"Dean Del Mastro then submitted this invoice to the campaign and was reimbursed $1,575 ... for a contract which he never paid," the court documents say.

'Followed all rules'

Del Mastro said Wednesday that he wrote the cheque but said he did not break any rules.

"I followed all rules. I always have. I always will," he said. "All my campaigns are above board. And I stand by those statements 100 per cent."

Del Mastro said that in the past, all his campaign expenses had been "reviewed, audited and approved" by Elections Canada.

None of the allegations against him have been proven in court and no charges have been laid.

Del Mastro was in Peterborough to announce an $8-million investment fund for the region.

The money comes from a larger $20-million fund from the FedDev Ontario's Prosperity Initiative for the province and will provide loans to local small and medium-sized businesses.