It's true, foreign actors rarely use their natural accents on American television. I kind of wish they would, more often. I think every other person I look up on IMDb is Canadian (a lot of Canadians don't have a discernible Canadian accent anyway), but there are also lots of Aussies and Brits. Off the top of my head, the only actor on an American tv show I can think of who uses his normal accent is Rahul Kohli on iZombie (and his castmate Rose McIver, who's from New Zealand, doesn't use hers). I think there are many film & tv actors who just stick with their American accent when doing interviews and public appearances here, so in some cases you'd really never know if you didn't Google them. For example, I'm not sure I've ever heard Charlize Theron use her South African accent (and according to Wikipedia, Afrikaans is her first language).