Mr. Harper responded to the controversy during the election, by pointing out that the candidate Mr. Soudas preferred, Robert Abdallah, was not appointed to the board in the end. He was later hired by one of Mr. Accurso's firms.
Mr. Poulin's name, along with Sen. Housakos', appears on the guest list of a more exclusive event held just before the main fundraiser, on May 20. That event was a reception with Prime Minister Harper.
Over the course of the spring, individuals associated with a range of other Montreal engineering firms were making donations to the Conservatives.
The Laurier-Sainte-Marie Tory association received nearly $10,000 from more than a dozen employees of CIMA, one of Quebec's largest engineering-consulting firms and a member of the consortium that won the contract to study the Champlain Bridge.
Sizable contributions were also received that spring from employees with other engineering firms, including CIMA, with no ties to criminal allegations.
For Mr. Housakos, the donations from engineering firms shouldn't be viewed in a negative light. He pointed to the transparency of the donation process in Canada and stressed the right of industry players to get involved in politics.
“It's pretty clear the people that make contributions,” Mr. Housakos said.
“If you look at various reports you'll know who they are. Their names speak for themselves. Those are my friends, that is my network, and I have a democratic right to solicit people.”
But whistleblowers have suggested that some engineering firms have been the link between corruption in the construction industry and the illegal financing of provincial political parties.
Lino Zambito, a construction boss who recently pleaded guilty to trying to fix the 2009 municipal election in Boisbriand, told Radio-Canada last month that engineering firms are “the ones closest to power.” He said they ask construction companies for a “helping hand” in order to secure certain contracts.
In 2010, the engineering firm Axor and several affiliated companies pleaded guilty to 40 counts of breaking Quebec's election laws.
The province's elections watchdog discovered the firm had circumvented laws preventing corporate donations by funnelling money through employees.
That forced the governing Quebec Liberals to return more than $113,000 in donations collected between 2006 and 2008. Opposition parties, the Parti Québécois and the now defunct Action démocratique du Quebec, returned smaller amounts.
Federal fundraising laws also forbid corporate donations, while limiting individual ones to $1,100 annually, indexed to inflation.
Like their Liberal counterparts in Chambly-Borduas, the Tories in Laurier-Sainte-Marie transferred much of their funds to other Conservative ridings.
The biggest recipient was the Conservative association in Megantic-L'Erable – the riding held by Paradis – which received $30,000 in the fall of 2009.
His office said he didn't recognize any of the names of BPR employees who were arrested.
Arguably the key figure in last month's arrests was the construction entrepreneur Mr. Accurso, whose name figured in the first news reports several years ago about close ties between municipal politicians and the construction industry.
Those initial reports opened the floodgates to myriad allegations, police investigations and, now, a public inquiry about to begin. Mr. Accurso now faces six charges: fraud, conspiracy, influence-peddling, breach of trust and two counts of defrauding the government.
More recently, a Radio-Canada investigation attempted to shed new light on how corporate interests might seek to gain political influence.
An undercover reporter posing as an investor recorded Pierre Coulombe suggesting that decision-makers in the Quebec government could be accessed, for a fee. Mr. Coulombe is an influential provincial Liberal organizer, and was recently a prominent Tory organizer.
He was overheard suggesting to clients that instead of paying off political insiders, they should simply promise future jobs.
He suggested some working conditions: the job might pay politicians, upon retirement, about $25,000 a year for multiple years and require them to attend only one meeting annually – while sending them on the occasional business trip to Europe, he said.
After the broadcast, Mr. Coulombe explained that he had actually been exaggerating on the video and had overstated his level of access to government contacts.
Mr. Coulombe was the chief organizer for the Harper Conservatives in Quebec from 2006 to 2008.