The suspect arrested Monday in Ottawa is now reported to be linked to the British bombing plot.
Mohammad Momin Khawaja, a Canadian government computer specialist, was held in Ottawa on Monday.
He was later accused of involvement in terrorist activity around the London area.
Early on Tuesday morning 700 British police raided 24 addresses in the South East of England, arrested eight young men and recovered half a ton of ammonium nitrate fertiliser – favoured by terrorists for manufacturing bombs.
Late last night police were granted another three days to question the suspects, meaning they can be detained under the Terrorism Act until Saturday afternoon.
It was also disclosed that a number of the eight – all British citizens mainly of Pakistani descent – had attended al-Qaeda training camps in Afghanistan.
Canadian suspect Khawaja, 29, was arrested at the Foreign Ministry offices where he worked.
Yesterday his father, Mahboob Khawaja, a university prof living in Saudi Arabia, called the raids in Canada and London “a hoax to create embarrassment”. Today the Saudis detained him, too..