The common-law wife of a man facing charges in a G20 security investigation has been charged with explosives offences.

Toronto Police say they have arrested Kristen Peterson, 37, of Toronto, Wednesday and charged her with possession of an explosive device and possession of a weapon for a dangerous purpose.

The arrest came after Toronto police and Ontario Provincial Police conducted searches at a home in Toronto, a property in the township of Tiny, near Midland Ont., and a property in the Township of Lake of Bays, near Algonquin Park.

Police won't say what prompted Wednesday's arrest, but it comes just a few days after a second person was arrested on similar charges. Byron Sonne, 37, faces several charges including possession of explosives, weapons dangerous, intimidating a justice system participant and mischief.

The same Toronto address – 58 Elderwood Drive, in an affluent neighbourhood in the city's north end -- was given for both Peterson and Sonne.

Peterson will be back in court on Saturday.

Sonne appeared in court Wednesday on the charges and was described as a highly skilled Internet expert who was critical of the summit's $1-billion security tab.

The Crown and police have said the investigation is ongoing and police will only say it relates to G20 summit security.

Sonne is also due back before a judge on Saturday for a bail hearing, in a special court set up to deal with cases related to the G20 summit.

The special court will be in operation daily until next Wednesday, from 2 until 9 p.m., every day including Saturday and Sunday.