Jim Prentice says he has no idea why receipts were destroyed from when he was a federal cabinet minister.

Prentice, a former Calgary MP, is running for the leadership of Alberta's Progressive Conservative (PC) Party.

“There is no reason for me to destroy documentation such as this. It should be available,” he said.

"I've always been of the view it should be available. Any expenses I have ever claimed have been substantiated by receipts. But I have no control, as a private citizen, over how the government in Ottawa is managing the records."

Receipts requested

Earlier this year, the Canadian Taxpayers Federation made a freedom of information request for expense records during Prentice's time with the ministry of aboriginal affairs and northern development. Such financial information is supposed to go to the archives, but the organization was told the receipts had been destroyed.

“We wanted to see if he was putting his money where his mouth is. And we can no longer prove that,” Alberta director Derek Fildebrandt said.

“Those records have been destroyed. We don’t take politicians’ word for it anymore. We need the details. They said the information is available. It’s not available.”

Fildebrandt says the federal government should put all expense records online.

Airdrie Wildrose MLA Rob Anderson described the expense claims as "magically been lost and shredded."

"It's pretty hard to believe it wasn't done without urging from someone in his camp, and we'd like Mr. Prentice to answer to that."

Prentice says he was 'proactive'

Prentice, who refused to carry a government credit card when he was a minister, says he is been out of government for four years and left the aboriginal affairs portfolio in 2007.

“I have been always completely proactive in my disclosure of all information relating to my expenses," he said.

Prentice said if he becomes leader of the PC party, he would advocate for the Alberta government keeping ministers' receipts for as long as possible.

Calgary MLA Ric McIver and Edmonton MLA Thomas Lukaszuk are also vying to replace Alison Redford as party leader. Redford stepped down as premier and leader in March.

Dave Hancock has been serving as the interim premier for Alberta until the party holds its leadership vote in September.