MONTREAL - A star witness at Quebec's construction inquiry whose testimony pushed the mayor of Montreal to resign left a trail of questionable spending of public funds during his time working for Stephen Harper's Conservative Party, sources told QMI Agency.

Between 2007 and 2010, Martin Dumont worked as the chief of staff for three Conservative federal ministers: Jim Prentice, Josee Verner and Diane Ablonczy. Records show that Dumont was spending more than important ministers in Harper's own cabinet.

QMI Agency obtained some of Dumont's expense accounts during his time working for the Conservatives. Well-placed sources told QMI Agency that Dumont had serious problems with his expense accounts, particularly in 2009, while he was chief of staff for Intergovernmental Affairs minister Verner.

During a 10-month period in 2009, Dumont billed the taxpayer for $46,423 in travel costs - more than twice the amount that Verner charged.

In contrast, Prime Minister Stephen Harper's head spokesman at the time, Dimitri Soudas, expensed four times less than Dumont over the same period.

QMI Agency also discovered in Dumont's expense accounts that the former chief of staff often charged taxpayers for plane tickets to travel the route between Montreal and Ottawa, while his predecessors and successors mostly took the trip by car.

Dumont also charged $900 in coffee and refreshments during a three-month period in 2009.

Aside from his work in federal politics, Dumont was a former organizer for the political party of Gerald Tremblay, the former mayor of Montreal who resigned in November.

Dumont was a star witness at Quebec's construction inquiry in 2012 and testified that he, Tremblay and a party employee were in a meeting in 2004 when the employee said the mayor's party had an official budget and an unofficial budget.

Dumont added that the party was so awash in money by 2004 that he once had to help the chief fundraiser shut the door of a safe overstuffed with cash at party headquarters.

Tremblay resigned as mayor shortly after Dumont's testimony.

Dumont is scheduled to testify once again at the inquiry, however, his lawyer has submitted a motion to delay the testimony due to Dumont falling ill.
Montreal's corruption inquiry has been on winter hiatus and is

scheduled to re-start on Monday.

Dumont did not respond to QMI Agency's interview request.