Why was the office of Prime Minister Stephen Harper so intent on placing Robert Abdallah at the head of the Port of Montreal?

The Conservatives have never answered that question, despite years of opposition hammering in the House of Commons, investigative news reports and parliamentary committees. Now the former top Montreal bureaucrat's name has popped up at Quebec's corruption inquiry, pushing the issue back to the surface again.

"There are names that keep coming up, and we wonder what their interest was," NDP MP Alexandre Boulerice said Tuesday after raising the issue during question period.

"Why did the Conservatives want so badly to appoint Abdallah there?... It will be up to the courts to shine the light on this. But we wanted the Conservatives to answer our questions. Unfortunately, they don't respond."

Former construction executive Lino Zambito told the Charbonneau commission Tuesday that Abdallah was part of a kickback scheme inside the City of Montreal.

Zambito said he had been told through a go-between in 2005 that Abdallah wanted him to use pipes from a particular firm while working on a sewer contract, even though they were more expensive. Zambito said he understood Abdallah would be pocketing hundreds of thousands of dollars.

None of the allegations have been proven in court, and Abdallah vehemently denied them Tuesday, calling Zambito's allegations a "pack of lies."

Abdallah was the Montreal's city manager in late 2006 when one of Harper's closest aides, press secretary Dimitri Soudas, began telling port board members the bureaucrat was the federal government's preference for president.

Mysterious telephone recordings, which surfaced last spring, purport to capture the voices of two construction bosses, Tony Accurso and Bernard Poulin, around the same time period discussing how Soudas could help them get their preferred man appointed to the port. Conservative Senator Leo Housakos is mentioned as a intermediary. Both Housakos and Soudas had worked in Montreal Mayor Gérald Tremblay's administration.

In another conversation purporting to be between Accurso and a man named "Frank," the pair discuss how former Conservative cabinet minister Lawrence Cannon had been instructed to appoint "Robert."

"I'm going to see Robert now, he's really happy," the man purported to be Accurso says on the recording. "But now this has to happen and it has to happen fast, because a federal election is coming."

Accurso and Poulin have never directly responded to questions about the tapes other than to point to Quebec laws prohibiting the interception and broadcast of private conversations.

Abdallah was later appointed to an executive position at one of Accurso's firms.

Soudas did not respond to a request for comment Tuesday, but in the past he has been adamant that he knew nothing about the discussions.

"I can't speak to private discussions of individuals, but... it's crystal clear, anyone who wants to influence the Prime Minister's Office, they will find the door padlocked," he said last April.

Soudas has emphasized that Abdallah was never selected by the board — a position echoed Tuesday by the Conservatives.

"The president of the Port of Montreal is appointed by the board of directors, not by this government," said Pierre Poilievre, parliamentary secretary to the transport minister. "In fact, they decided not to appoint that individual."

Soudas told a Commons committee in 2008 that he had never personally met with members of the port authority to discuss the appointment. That was later refuted by the chairman of the board, who said there indeed had been a meeting in late 2006 between Soudas and some board members at a Montreal restaurant.

When the purported recordings of Accurso and Poulin emerged during the federal election campaign last spring, Harper stood behind Soudas, who now works with the Canadian Olympic Committee.

The Prime Minister's Office did not respond Tuesday to questions.