A federal official has conceded that the government does not have the legal right to indefinitely detain foreign-born terrorist suspects who cannot be deported. But Alex Swann, a spokesman for Public Safety Minister Anne McLellan, said the government intends to aggressively pursue the deportation of terror suspects through the controversial security certificate process. And the question of when that pursuit formally ends is something that may have to be decided by the Supreme Court. "As long as we're working through the security certificate process with the aim of removal, that (detention) continues to be an option," Mr. Swann said. "When a deportation is unsuccessful, I don't know when that time comes," Mr. Swann said. Mr. Swann maintained the question of when the government must end its pursuit of a terrorist suspect's deportation remains hypothetical. The Immigration and Refugee Protection Act, which sets out the security certificate process, allows the government to detain foreign-born terror suspects on the strength of secret evidence until they can be deported.