With the case against several G20 protestors settled with a plea deal, more details are being revealed about undercover police operations in the year before the riot.

The RCMP calls the operation one of the largest in Canadian history, and some did take place in southwestern Ontario.

In fact, the case against those charged in last year's G20 riots was largely based on the evidence collected by undercover officers who befriended protesters a year earlier.

According to documents obtained by CTV News, there were as many as 12 police informants, with the two most successful based in Kitchener and Guelph.

Activist Julian Ichim was befriended by one of the informants, an OPP officer, and even considered him a close confidante.

But it turns out he didn't really know the man, posing as a Kenyan immigrant who had participated in that country's resistance movement, at all.

"The first time we made contact was at the Anarchist Book Fair…His recklessness and extremes meant to me that his heart was in the right place," Ichim says.

He was so trusted that when activists worked to stop construction at Guelph's Hanlon Creek Business Park in 2009, the informant was a dedicated member of the group.

That occupation lasted three weeks, with the city later filing a lawsuit seeking millions in damages.

Activism isn't cheap, and Ichim says the man often brought booze and offered to drive when needed, "Being a political organizer you don't get a lot of money and hitch-hiking is really hard."

He even offered to drive to events like the Olympic Torch relay to protest as it passed through a number of locations, including Guelph, Kitchener and northern Ontario.

In fact, Ichim says the officer was one of the big organizers of the torch protest and was even arrested while trying to block the flame in northern Ontario.

The level of involvement of undercover officers in planning the G20 riots remains unclear, but there are reports they helped choose the group's targets.

Ichim was arrested before Toronto's G20 riot started, and that was when he realized what had happened.

"Later we found out they had a police profile on me and that this agent had used the profile to say all the right things."

Ichim was so upset he wrote about the betrayal on his blog, in violation of a publication ban, and is now facing charges.

That same publication ban is the reason CTV News is only now reporting on the undercover operations, after the court case has concluded.

Protestors say they should have been more suspicious of their new friend, because he always asked for receipts at the bar.

Meanwhile police have refused to disclose how much the undercover operation cost taxpayers.