Winnipeg's mayor says he was contacted on his private cellphone by a lawyer representing an anonymous group that paid for private investigators to tail city building inspectors and he was offered a copy of their confidential findings.

Brian Bowman told reporters Thursday the lawyer called him Easter Monday but he declined to accept the package.

"I encouraged him [the lawyer] to make whatever information they felt they could make available to the public service that's currently conducting their investigation," Bowman said.

"There was no answer given as to how he got my private phone."

The lawyer said the documents, which Bowman was told included surveillance video, would only be provided under the condition the mayor didn't share them with internal investigators, a condition Bowman said he would not accept.

Media outlets, including CBC, received a package of materials, including written reports and DVDs, that purport to show more than a dozen building inspectors shirking work duties and carrying out personal business, including errands and shopping.

CBC has not independently verified the materials; however, a report by the Winnipeg Free Press prompted the city to launch an internal investigation into the allegations.

Bowman said he told the lawyer to contact the provincial ombudsman and provide the documents to the office. He also told reporters Thursday he wrote a letter asking the ombudsman contact the lawyer directly.

"I think there may be some confusion about the powers and the abilities of the ombudsman," Bowman said.

"I did ask respectfully that the ombudsman reach out to the lawyer to just apprise about what is the whistleblower protection and could it be, possibly, utilized."

Official leading probe resigns

The person leading an investigation into allegations city building inspectors conducted personal business on the taxpayers' dime, is leaving the city's public service, city council learned Thursday.

In an email sent to the mayor and members of council, the City of Winnipeg's chief administrative officer, Doug McNeil, said Robert Kirby has accepted a job outside Manitoba.

Surveillance video claiming to show city inspections staff shopping during business hours was submitted to CBC Manitoba but has not been independently verified. (Submitted) "We are disappointed that Robert will be leaving, and I hope you will all join me in wishing him all the best in his future endeavours," McNeil wrote.

Kirby, Winnipeg's manager of labour negotiations, is leading the wide-sweeping investigation at the property and planning department into allegations city building inspectors were using work hours to conduct personal business.

So far, the city has interviewed nearly 70 employees to determine whether there is any truth to the private investigators' findings as reported in the media.

McNeil is counting on Kirby to complete the investigation, which along with interviews also includes reviewing employee mileage logs and inspection reports, before he leaves May 24.

Contract negotiations

"In regards to the staff investigations, the initial investigations are near completion, and we are confident that Robert will be able to conclude this work before his departure and that staff in his division will be able to deliver on any next steps," said McNeil.

In his two years working for the city, Kirby negotiated six contracts with unions and is in the middle of negotiations with Winnipeg's transit union.

Winnipeg's senior labour relations officer, John Dawson, will takeover negotiations with the Amalgamated Transit Union if negotiations are not complete before Kirby's departure.