British Columbia's privacy watchdog has launched a formal investigation to determine whether the provincial NDP is breaking the law by demanding potential leadership candidates hand over the passwords to their social media accounts.

The Opposition party has asked candidates running for the April 17 leadership vote for the login information to their online profiles as it attempts to vet them for anything that could come back and haunt their campaigns, such as embarrassing photos or Internet postings. The New Democrats lost a candidate in the 2009 election after racy Facebook photos surfaced in the media.

But Elizabeth Denham, B.C.'s information and privacy commissioner, said in an interview Friday that she's concerned the party may be running afoul of provincial legislation.

The commissioner said privacy legislation sets limits on what information private entities -- including political parties -- can collect. That information must be reasonable, relevant, accurate and effective for whatever purpose it's being collected.

Denham said she's concerned the NDP's policy doesn't meet those standards.

"At first blush, I think the idea of a political candidate having their full social media profiles examined and vetted appears to be problematic from a privacy perspective," she said.

"Social media profiles are really a mix of public information and private information. So giving somebody the keys to the castle, the password to a social media profile, really opens up a lot of information that an individual may want to keep private."

The party is currently in the midst of a leadership race to replace former leader Carole James, and each candidate must fill out a disclosure form detailing anything about their past that could become controversial.

Included in that form is a space for candidates to list the login and password information for their online accounts.

Nicholas Simons handed in his nomination package, complete with a $15,000 deposit, without his passwords, explaining that he hopes the party can figure out another way to scrutinize his personal life that won't be so intrusive.

Simons has said he's concerned not just for his own privacy, but for the privacy of anyone in his Facebook network, whose information would be readily accessible to anyone with access to his account.

Jan O'Brien, the NDP's provincial secretary, said the party gave the login information to an independent researcher, who signed a confidentiality agreement.

The researcher has already finished examining profiles for every candidate other than Simons, said O'Brien, adding that the party is working with Simons to find a compromise.

O'Brien defended the policy, noting politicians' lives are far more public than ordinary citizens.

"These candidates are seeking the top position in the party, they're asking the BC NDP to put all their resources behind them to become the premier of the province," O'Brien said in an interview.

"Our goal from Day 1 has been to work with candidates if there's anything that comes to our attention and help them get past it."

O'Brien said the party introduced the policy after racy Facebook photos forced Vancouver-area candidate Ray Lam to drop from the race during the 2009 provincial election.

Denham said her investigation, which she launched on her own without first receiving a complaint, should take a few weeks, after which she will make recommendations for the party.

"They want to make sure that there's not embarrassing information out there, I can understand the purpose," Denham said.

"But maybe there are other ways that they can meet that purpose without requiring the credentials of somebody's personal social networking site."

She suggested an alternative is educating candidates "about what kind of social media activity is appropriate, and how certain actions can actually hurt your reputation."

Simons, who is still waiting to learn whether his refusal to hand over his passwords will affect his candidacy, welcomed the privacy commissioner's investigation.

"It's an important new area that requires some clarification for people," he said. "From my perspective, I'm dealing with this issue with the party and we're getting through it and we're going to find a solution."

The former NDP candidate whose failed 2009 campaign appears to have prompted the policy said he thinks candidates don't always know the consequences of what's on their online profiles.

Ray Lam stepped down as an NDP candidate after photos emerged that showed him, years earlier, posing with his hand on a woman's breast in one photo and with his pants down in another.

Lam said the images were from his high school days, and were actually posted by somebody else, who "tagged" him in the photos. He said he was surprised at the "Liberal spin" that followed, with Premier Gordon Campbell using the occasion to attack the NDP and incorrectly suggesting the photos were posted to the party website.

"We're candidates, we're not communications experts, and it's really hard for candidates to gauge how things that we find innocuous could be spun into major issues by our opponents," said Lam.

"That's why I very strongly believe in the vetting process. You need someone experienced in the field of communications and aware of the political landscape that would be able to say, 'These are political time bombs. We need to get rid of them."'