MONTREAL -- A little more than a year ago, Saulie Zajdel joined Stephen Harper for a happy-hour pub stop in Montreal as perhaps the Conservatives' best hope to win their first seat in this city in a quarter-century.

Today, Zajdel is under arrest.

The Conservative election candidate was picked up Monday along with Montreal Mayor Michael Applebaum and now faces five charges from acts allegedly committed back in his days as a municipal councillor.

The charges include breach of trust, fraud and corruption linked to alleged activities that took place between Jan. 1, 2007, and Dec. 31, 2008.

Zajdel, 57, narrowly lost to Liberal incumbent Irwin Cotler in the 2011 election and, after the vote, was put on the payroll in a minister's office to work on ethnic outreach.

Cotler had raised concerns that Zajdel was earning a government paycheque while trying to perform MP-like duties in his Montreal riding.

He had described Zajdel as a "shadow MP" in his riding of Mount Royal, a complaint that followed reports of mysterious phone calls to his constituents that suggested the former justice minister, then 71 years old, was on the verge of retiring.

Zajdel abruptly resigned from that federal job last spring.

A couple of weeks before he quit, Zajdel had been part of Harper's entourage during the prime minister's visit to Montreal, which included a public event just a few hundred metres from the border of Cotler's riding.

Harper and Zajdel also made an appearance together in March 2012 at an Old Montreal pub where they met with party supporters.

The Harper government quickly distanced itself from Zajdel on Monday.

It confirmed that Zajdel worked in the office of Heritage Minister James Moore from October 2011 to March 2012 as a liaison with Montreal's cultural communities.

But in a statement it said none of the allegations against Zajdel were known at the time, and a normal screening process was done.

A spokesman for the Conservative Party also reacted Monday to Zajdel's arrest.

"This was a surprise to us," Fred DeLorey wrote in an email.

"He did not disclose this to us through the screening process, nor did this come up in the background checks. He'll need to face the consequences if he broke the law in any way."

Zajdel finished some 2,300 votes behind Cotler in the May 2011 election in Mount Royal -- a riding coveted by the Tories as a possible beachhead in Canada's second-largest city. The riding, once represented by Pierre Elliott Trudeau, has been Liberal since 1940.

Cotler urged people not to rush to judgment against his rival.

"I was made aware of the arrest of Saulie Zajdel from media reports this morning. Everyone benefits from the presumption of innocence," Cotler tweeted Monday.

"Thus I have no comment while the police investigation and related process in this matter are ongoing."

Zajdel had been a city councillor in the same Cote-des-Neiges-NDG borough as Applebaum, and the two of them were part of the once-mighty Union Montreal political party, which had won every election in the post-2001 mega-city.

Applebaum, meanwhile, will face 14 charges including fraud, conspiracy, breach of trust, and corruption in municipal affairs.

Union Montreal dissolved last month after corruption scandals pummelled city hall. It was also the party of Gerald Tremblay, the longtime Montreal mayor who resigned from office last year amid the same political storm.

Zajdel spent years on the city's powerful executive committee in areas such as zoning and urban planning, according to Zajdel's LinkedIn profile.

The online profile said he had spent the last year as a real-estate broker and a municipal-affairs consultant with expertise in matters related to zoning, urban planning and permits. The profile, however, makes no mention of Zajdel's federal work for Moore's office.

When it came to details about Zajdel's federal job, information wasn't always as easy to find.

The Conservatives had been reluctant last year to discuss his duties or his salary in the government position.

But the Tories eventually broke their silence when Moore himself came out in defence of his employee, who left Montreal municipal politics in 2009 after 23 years on council.

Moore shared some details about the job, explaining that Zajdel worked in his Montreal office as a non-partisan liaison with local ethnic communities.

"Saulie was a multi-term councillor here in Montreal and he knows people and people know him," Moore said in March 2012.

"They also know that he's a hard-working, decent guy who wants to do good things for Montreal and he was unsuccessful in the campaign, but he wants to continue to serve and he's done a great job."

Zajdel's federal appointment first caught Cotler's attention after the defeated Tory candidate convened a meeting with municipal politicians in Mount Royal to explain the grants and programs offered by Canadian Heritage.

One mayor who attended the November 2011 presentation said while it was unusual to receive such an invitation from a government employee, he noted that Zajdel didn't raise partisan politics.

In his federal role, Zajdel also spoke publicly in Cotler's riding, which has a large Jewish population, about Canada's relationship with Israel.

Zajdel declined multiple interview requests to discuss his Canadian Heritage job, but he spoke candidly about his government paycheque in a chat with a Canadian Press reporter during Harper's March 2012 Montreal visit.

He revealed that he was earning less than he had hoped for.

"Oh, (it's) not as much as I want it to be," Zajdel said. When asked how much he would have liked to earn, he replied: "Something in the six digits and it's not that."

Zajdel announced a couple of weeks later that he had stepped down from his federal job. He told a Montreal radio station that he decided to quit because the controversy stirred up by the position had overshadowed Harper's announcement in the city.

"I was tired of being this distraction," Zajdel said in a radio interview with CJAD, before adding that it would be his "greatest pleasure" to run again for the Tories.

- with a file from Joan Bryden in Ottawa