The government's proposed anti-terror legislation expands the powers of Canadian Security Intelligence Service to allow it to "disrupt" suspected terrorist threats — but it also expressly prohibits CSIS from killing or seriously injuring a subject.

What's not clear exactly is where the line between those activities is drawn and what that means for the agency when it comes to interrogation techniques, experts on civil liberties and security point out.

Bill C-51 would allow CSIS to take measures within or outside Canada to reduce threats to the security of Canada, but doesn't spell out exactly what those measures could be. The bill lists prohibited activities, barring CSIS from:

Intentionally or by criminal negligence cause death or bodily harm.

In any way trying to obstruct, pervert or defeat the course of justice.

Violating the sexual integrity of an individual.

The bill ties "bodily harm" to its definition in the Criminal Code, which means any injury to a person that "interferes with the health or comfort of the person and that is more than merely transient or trifling in nature."

Observers say it's too early to know exactly what that section means. And, given the agency's new ability to "disrupt" and to trigger preventative detention, they say further explanation is needed.

'Anything except bodily damage'

"We don't know what the power to disrupt means. At first reading it seems that [CSIS] can do just about anything except bodily damage or assassination or sexual abuse," said Roch Tassé, a spokesman for the International Civil Liberties Monitoring Group​.

But there are other provisions that would let CSIS request a warrant to enter any place or open anything; search, copy, remove or return any record; install or remove anything; or "do any other thing that is reasonably necessary to take those measures."

"Basically they'll be allowed to break the law. They'll go to a judge to get permission to break the law," Tassé said.

Sukanya Pillay, executive director of the Canadian Civil Liberties Association, said the section of the bill on CSIS is confusing because "we know that you can't get a warrant to contravene the charter."

The prohibitions on causing bodily harm and sexual violation are also troubling, she said, because it's not clear what they mean.

"Are these intended to be sort of putting the brakes on the behaviour? And if they're meant to be putting the brakes on CSIS's actions, then the next question is just how far and how fast are we expecting CSIS to go with these new powers," Pillay said.

Pillay said that section could be in the bill because the government was trying to be diligent and exclude those actions, but in the broad context of the increased powers for CSIS, it doesn't look like it.

Psychological harm not mentioned

The U.S. Central Intelligence Agency was condemned as recently as last December for its use of enhanced interrogation techniques, including sleep deprivation, confinement in small boxes, nudity, death threats, ice baths, shackling in the cold and more.

A spokeswoman for Public Safety Canada repeated the definition of bodily harm in a short response emailed to CBC News.

"I can tell you that Canada does not engage in, or condone the use of torture. As well, the Anti-terrorism Act, 2015, makes it clear that in taking measures to reduce a threat to the security of Canada, CSIS may not cause bodily harm," Lisa Filipps wrote.

Liberal public safety critic Wayne Easter, a former solicitor general, said he isn't concerned about the provisions, but wants to hear from legal experts and stakeholders.

"I took it to mean ... that it's prohibitions to give greater certainty that [abuse] couldn't in fact happen by CSIS agents because that's not the way we do things in Canada," he said.

Michael Kempa, an associate professor at the University of Ottawa, said the provisions don't rule out all abuse.

"What about psychological harm?" Kempa said. "[The reference to] bodily harm is you cannot inflict physical damage. It doesn't mean that you cannot use any implied physical threat or you can't psychologically browbeat someone in an interrogation."

Kempa, who is campaigning to run for the Liberals in a Toronto-area riding, said physical tactics aren't ruled out entirely.

"That's very, very broad," he said.

The bill would require CSIS to report publicly on what actions it takes to disrupt threats, the number of warrants issued and the number of applications for warrants refused, and a general description of the measures taken under the warrants issued.

Critics said CSIS, which is overseen by the Security Intelligence Review Committee, is already not accountable enough.