It can get tricky to match in wider shots, though. And be sure to use a 3200K tungsten source. For the close ups, I threw in a couple of white papers on the table underneath the actors to bounce some light onto their faces. If you want some light on the background, use some foamcore as mentioned above. It's very much up to the media you are using.
Some interrogation scenes use glow to emphasize the light that's pouring onto the subject.
A double-fog or white mist lens filter is used for this or a glow filter applied in post. Another crazy idea I read about involves a hula hoop. Center a 1K open face in the circle at the top edge of the duveteen. Suspend this apparatus directly above the subject's head. You may need some diffusion on the broad to make this look good.