The Keeyask generating station will generate another 695 megawatts from the Nelson River, which already produces almost 4,000 megawatts. (Manitoba Hydro)

A taxpayers' watchdog group said Thursday it has obtained a leaked Manitoba Hydro audit document that raises questions about the crown corporation's spending on dam negotiations.

The Canadian Taxpayers Federation said the audit looks at how Hydro reimbursed York Factory First Nation for the First Nation's expenses from 2011 to 2013 during negotiations over the proposed Keeyask generating station.

The audit found discrepancies in airfares, mileage claims and what it called "non-compliant items."

The expenses totalled $5.4 million.

The CTF says dam negotiations have cost the Crown corporation more than $250 million over the past 14 years and that these secret expenditures need to be made public.

"What we want to see is transparency," said the CTF's Colin Craig. "We want to know where the money has gone. We want to see audit documents from all the years Hydro has looked at these expenses."

In response, spokesperson for Hydro says the provincial ombudsman has already ruled that making these financial agreements public would harm third party business interests.

"They [CTF] keep going back to well on this issue," said Scott Powell.

Powell said the leaked audit proves what Hydro has said all along; that it is diligent and that it reviews all expense claims.

Powell said Hydro is now reviewing the audit results to see if it will demand York Factory pay some of the expenses back.

A phone call to the York Factory band office was not returned.