A computer security expert arrested on explosives and weapons charges in a G20 security case has been denied bail for a second time.

Ontario Superior Court Justice Janet Wilson gave her decision Friday on Byron Sonne’s bail appeal but did not read out her reasons, which are subject to a publication ban.

Sonne looked at his parents, mouthing that he loved them, and punched the air with his fist in what supporters called a non-offensive but defiant gesture before he was led away.

He is being held at Maplehurst Correctional Complex in Milton.

“We all are obviously disappointed and will continue to work for Byron,” said his lawyer, Kevin Tilley.

The next step in his case is a preliminary hearing in provincial court.

Sonne, 37, was arrested on June 22 when police converged on his million-dollar Forest Hill home, days before world leaders descended on Toronto for the G20 summit.

He faces charges of possession of explosives and dangerous weapons, as well as intimidation of a justice system participant and mischief.

In late July, Justice of the Peace Mary Anne Ross-Hendricks ruled that Sonne must remain in jail. But Sonne appealed her ruling in Ontario Superior Court, which led to Friday’s second denial.

Madison Kelly, of the Free Byron campaign, said she could not understand why he is being held.

“As a layman, I can’t help but feel that there is more to this case than what you are seeing on the surface,” said Kelly, one of more than 20 of his supporters at the courthouse.

She said Sonne’s supporters — a “loose community of hackers, tinkerers, makers, amateur scientists” — will continue to work to clear up public misunderstanding of what he and they do, she said.

Their members are driven by simple curiosity about how the world works, she said.

She said that since Sonne’s arrest there is a lot of “self-censorship” in the group because they fear they may end up being arrested if they “upset the wrong person.”

Sonne’s parents, Valerie and Bue Asbjorn Sonne, who were at the hearing, declined comment.

The day after Sonne was arrested, Sonne’s artist wife and co-accused, Kristen Peterson, 37, was taken into custody and charged with weapons and explosives offences.

She has been free on bail since June 26. Her conditions include living with her parents, and having no contact with Sonne except in the presence of lawyers.

Colleagues have described Sonne as well-respected in his field of computer security. He previously worked for top companies such as nCircle Network Security and FSC Internet Corp.

A former boss said he was now running his own computer security consultancy called Halvdan.