A Toronto activist has been acquitted on charges of possessing explosives and counselling mischief in connection to the Toronto G20 Summit riots.

Byron Sonne, 39, was acquitted of all five charges as his trial concluded on Tuesday.

Sonne was arrested days before the June 2010 summit and remained in jail for 11 months before he was released on bail.

Police seized a quantity of chemicals including hexamine fuel from his Toronto home and alleged the self-described security geek was planning to make bombs to use during the summit of world leaders.

Sonne, who is a computer programmer and a hobby chemist, admitted to having chemicals at his home that could be combined to make explosives, but said he never combined or "weaponized" them.

His defence team argued that Sonne made poor decisions in trying to expose the exorbitant $1-billion G20 security system by showing how easy it was to hack. He was also trying to prove that one could access the materials to make explosives without getting caught, his defence team said.

Sonne had been charged with four counts of possessing explosives and one count of counselling mischief for allegedly urging others to scale the security fence built around the downtown Toronto summit site.

On Tuesday, Ontario Superior Court Justice Nancy Spies said the Crown failed to prove Sonne was planning to combine materials to create a bomb, acknowledging it was plausible that he had the chemicals because he was a rocket hobbyist.

Sonne thanked the judge after the verdict on Tuesday, as a downtown Toronto courtroom packed with supporters erupted in applause.

During the trial, the court saw hundreds of photos taken by Sonne of security measures including surveillance cameras, police and portions of the security fence.

The Crown also relied on the testimony of an explosives expert who said Sonne had enough material to blow up a bus.

Sonne's wife was also arrested ahead of the G20 Summit but the charges against her were dropped.

The couple has since split up and Sonne has been living with his parents since his release on bail last year.

Five other charges against Sonne were previously dropped, including mischief, possession of a dangerous weapon and intimidating a justice system participant.

Sonne faced up to 10 years in jail had be been convicted.

With files from CTV Toronto's Michelle Dube