​Daniel Radcliffe goes undercover in "Imperium"

Daniel Radcliffe's latest role

In the five years since graduating from Hogwarts, Daniel Radcliffe, star of the "Harry Potter" movies, has played such varied roles as a famous poet and a talking corpse. In his new movie, "Imperium," he plays Nate Foster, an FBI agent who goes undercover to join a white supremacist group plotting a race war.

Actor Daniel Radcliffe. CBS News

When asked on "CBS This Morning" about preparing for the role, Radcliffe said, "I was really lucky to be able to talk to Mike German, who helped write the script along with Dan Ragussis, our director. Mike is a former FBI agent who was undercover for various periods of time over about 14 years, and so to be able to pick his brains about why he went into that job, which is something that is way scarier than I would ever do and what that life is like.

"'Cause in films we are sort of used to seeing guys with guns and stuff, where it's if you fire a gun undercover you're the worst agent in the world. You have got your charm and your intellect and your ability to sort of talk your way out of a situation is really all you have."

Being undercover, Radcliffe agreed, is acting.

So what is the priority of an undercover agent when facing a situation where your cover may be blown, as in the scene in "Imperium" where the white supremacists encounter an interracial couple?

"My first question [to German] was, 'What is your first priority as an undercover agent? Is it to maintain your cover? What are you there to do?' He said, 'No, actually, your main priority is not only should you not be involved in a crime that's about to take place, you actually have the responsibility to prevent that crime from taking place,' despite the fact that that would possibly [blow your cover]. It's an incredibly complex world."

Daniel Radcliffe plays an FBI agent who infiltrates a right wing terrorist group in "Imperium." Lionsgate

CBS News correspondent Margaret Brennan asked Radcliffe about the fact that white supremacists are not commonly portrayed as "terrorists."

Radcliffe responded, "I think that is really important. I know that terrorism comes from everywhere. My dad is Northern Irish and he grew up there during the Troubles, so I always had that awareness it comes in all shapes and sizes. I think the more we stigmatize a certain group of people being associated with terrorism, there's something inherently just awful about that to me. "

He read the script around the time that Dylann Roof killed nine people at the Emanual AME Church in Charleston, S.C., in July 2015.

"I believe there was at the time a reticence among the higher-ups of officialdom to refer to that as terrorism when, obviously -- well, to me at least -- it is," he said. "So that seemed to be one of the points the film was making as well so that was seemed a very good point to make. "

"So you would call this terrorism?" Brennan asked.

"Absolutely. Any time you're hurting somebody with any sort of political ideology motivating it, I think that sort of qualifies. I think you could use broader terms in terms of just like any act of violence toward somebody else instills terror in somebody but that is probably not what most people mean by it."

Co-anchor Gayle King asked how difficult it was for Radcliffe to play someone spouting racist language.

"It's horrible -- even though you're acting, it's really horrible to say those words," he replied. "I found it so. I would, like, incessantly run up to the people I was throwing these slurs at between takes and say, 'I'm so sorry, I', so sorry.' Those words have power for a reason. Yeah, they feel very bad to say."

From Hogwarts to Broadway: Daniel Radcliffe

Radcliffe just ended his run on the New York stage in the play "Privacy." "Film is where I grew up and I'll always love being there, [but] every time I do a theater show I come away feeling I'm a better actor for it. I feel I learn something every time."

King asked Radcliffe if he is sick of people talking about Harry Potter.

"No, I'm not sick of it at all. I think people expect me to be sick of it, but I really love when people come out and say what a part of their childhood I am and all that. For me, I always use the example of, I loved 'The Simpsons' growing up, it was a huge staple of my childhood -- it was like, I made it when I did [voice work on the show]! -- and the fact I might occupy that space in somebody else's childhood is really special. And I had a great time on the films."

King asked Radcliffe if he could score tickets on "Harry Potter and the Cursed Child," the new play currently a smash hit in London (and which are being re-sold for up to $15,000): "I just said to somebody else, I cannot hook you up. I do not have any. Sorry!"

Would he go see the show? "I probably will read it, 'cause the script's just come out. I think sitting in that audience might be a slightly intense kind of experience, but if it calms down at any point, I will."

To watch a trailer for "Imperium" click on the video player below, or click here: