A trial begins in Winnipeg today for Aaron Driver, a man police fear may engage in terrorist activities.

The hearing begins Tuesday at 10 a.m. at the Winnipeg courthouse. It is expected to last up to four days.

Driver caught the attention of CSIS, Canada's spy agency, in October 2014 when he was tweeting support for the militant group ISIS under the alias Harun Abdurahman.

He was arrested on a peace bond in June 2015, as authorities were concerned he would become involved in planning terrorist activity. He has not been charged with any criminal offence.

He was later released on numerous bail conditions that, among other things, require him to:

Undergo religious counselling.

Wear an electronic monitoring device.

Surrender any passports he has and not apply for any passport.

Not possess any desktop, laptop or tablet computer.

Stay away from any social media websites.

Have "no contact or communication directly or indirectly with any member of ISIS, ISIL, Islamic State of Iraq and Syria and Al Qaida in Iraq." He is also barred from possessing anything bearing the logos or names of those groups.

Driver has since been living with his brother in Ontario, but he is in Winnipeg for this week's trial, which will determine whether or not he should enter into the peace bond.