British Columbia's top cop has found himself on the other side of the criminal justice system, facing an RCMP investigation that has forced him to resign from his post as solicitor general.

Kash Heed, a former police chief and star Liberal candidate in the May 2009 vote, announced his resignation Friday, citing allegations that his campaign office violated advertising and finance rules in the Elections Act.

RCMP confirmed a commercial crimes unit investigation and the criminal justice branch announced a special prosecutor has been appointed to oversee the case.

Heed said he has no idea what allegations prompted investigation, but he was adamant that, whatever they are, he had nothing to do with it.

"I am absolutely confident that I've done nothing wrong, that's why I'm going to fully co-operate with the RCMP and it is that reason that I'm stepping aside to maintain the integrity of this office and to maintain my integrity," he said at a hastily called news conference at his constituency office in Vancouver on Friday afternoon.

"I have no idea what this is about, but I can tell you again, I have done nothing wrong."

Neither Heed nor the RCMP are revealing many details.

Heed said he first learned about the probe at the end of March, from RCMP. But he said they originally told him he was not being investigated.

That changed earlier this week when he said he was told the RCMP were now looking into whether he had any role in the allegations, and on Wednesday he learned a special prosecutor had been appointed to the case.

In fact, Terrence L. Robertson was appointed special prosecutor in January, and the RCMP started their investigation within weeks of last May's election, which returned the Liberals to power for a third term.

Insp. Tim Shields said the investigation was prompted by a complaint to the province's chief electoral officer, who forwarded the allegation to RCMP last June.

Shields said a report to Crown counsel will be complete by June, noting a one-year statue of limitations on Election Act violations.

"The allegations are concerning the campaign office of Minister Kash Heed, and although there's more than one person who can potentially be involved, we're not going to be naming names," Shields told reporters.

"It's a very sensitive investigation, and the priority of police is to get to the truth and discover the facts."

Shields said several people from Heed's campaign office are under investigation, but declined to elaborate.

Heed is the third Liberal solicitor general forced to resign amid allegations of wrongdoing in the past two years.

John Les resigned from the post in March 2008 after it was revealed he was part of an RCMP investigation that alleged he improperly benefited from land deals while he was serving as mayor of Chilliwack.

And John van Dongen resigned as solicitor general in April 2009 after it was revealed he lost his driver's licence for numerous speeding tickets. He was serving as Superintendent of Motor Vehicles at the time.

Attorney General Mike de Jong will fill the position for now, although Heed said he plans to return to his cabinet post once his name is cleared. He will continue to represent his riding in the meantime.

Heed's profile rose while he was an RCMP district commander with a view to reducing property crime in south Vancouver. He spearheaded the creation of the gang violence task force, and is credited with reducing gang-related violence by more than 40 per cent, according to his website. He became chief of the West Vancouver Police in 2007.

But since announcing his entry into political life last year, Heed has been dogged by a defamation suit filed by a former West Vancouver officer.

Heed has spent his time in cabinet championing increased accountability for the RCMP, demanding the force change the way it investigate itself or risk losing its contract for provincial policing in B.C.

Jane Thornthwaite acknowledged in February she made a mistake after she was stopped by police for drunk driving.