The RCMP are investigating a payment made to a member of Winnipeg city council as part of the probe into cost overruns at the new police headquarters, reports say.

The Winnipeg Free Press quotes unnamed sources that say the RCMP are also looking at doctored invoices in connection to the project, which has soared $75 million over budget.

Mayor Brian Bowman said he's appalled with the allegations. 

"If it's true that members of the City of Winnipeg, elected or city employees have been doctoring invoices, if it's true that there've been under the table payments, it is appalling and perhaps it's time that heads should roll," he said. 

Bowman said it's upsetting that the new council has to deal with what happened under the old council's watch. 

Canada Post winnipeg police hq

The former Canada Post building on Graham Avenue is being redeveloped into a building that will house the Winnipeg Police Service's new headquarters. (CBC)

"We're still having to deal with nonsense like this," he said. "Nonsense that we've inherited that we need to deal with and we will deal with."

Bowman said the former council however did do the right thing by asking the province to step in and review audits of the city's new police headquarters, the construction of new fire-paramedic stations and city real estate transactions. 

However, he said he has not be made aware of how that review is proceeding but has asked the province for any information it can provide and is waiting to hear back whether that's possible. 

"I haven't been advised nor am I aware if this matter is being investigated or still just being reviewed," he said. "We're going to do all we can to get that information - if it can be provided to us - and if so of course we'll co-operate fully with the RCMP. We have to get to the bottom of this. It's something that needs to happen in order for us to be more effective here and to restore people's faith in city hall."

Bowman said he knows nothing about the allegations about doctored invoices or payments made to council members, emphasizing that at this point, there are merely allegations. 

"These are unproven and all I have to go with is allegations from one article at this point," he said.

Police chief Devon Clunis said his department was contacted about the allegations.

"I can tell you that information that came forward to us was acted upon. I would say that if there is additional follow up ongoing now by the RCMP, I would allow them to complete that portion of the investigation," he said.

Councillors shocked

It's unknown who is being targeted in the investigation, but councillors CBC spoke with Thursday are also shocked by the revelation.

Coun. Brian Mayes said the allegations go way beyond what was revealed in a series of audits completed by the city during the past two years into the police HQ.

"This is some new information, it appears, and they [RCMP] will have to deal with that as they see fit. I'm not going to second-guess the RCMP or the Winnipeg police as to how they are going to proceed with this," he said.

Mayes and a number of other councillors contacted by CBC News on Thursday say full investigations are needed to make sure city hall's dealings are transparent to the public.

Mayes and Coun, Jeff Browaty also told CBC they did not receive any payment.

"I know it wasn't me, so that knocks me off the list," Mayes said,

"I can go to bed at night obviously knowing I had no involvement in any of that. I was surprised to see it was an elected official that was named," Browaty said.

An external audit, released in July, detailed several "gaps" between how the project was handled and what current city policy is.

The KPMG report stated there was a lack of evidence to prove the required consultation was made with decision-makers, oversight committees and city council as the project moved ahead.

In 2009, the project was forecast to cost $135 million. But by fall of 2013, city council learned the costs had mushroomed to $210 million.

The headquarters — a redevelopment of the former Canada Post building on Graham Avenue — was first scheduled to open in January 2014. That date was postponed to June, and then this fall, when it was put off once again.

No new date has been set.

CORRECTION: A previous version of this story stated that Winnipeg Police Service Chief Devon Clunis told reporters that information regarding witnesses coming forward was passed along to the RCMP. In fact, Clunis said "No. That [passing along the information] was not required at that point."