Hi, this was recently a subject of much discussion. The short answer is that it's possible—there was long-distance slave trade, and Scandinavians were engaged with trade reaching into Central Asia and the Indian subcontinent—but it's not at all likely. The slave trade was moving in the wrong direction (toward the East Mediterranean and North Africa, not out to the Scandinavian hinterlands), and Scandinavians don't seem to have kept prestige slaves (having slaves might have made one prestigious, but it didn't matter how exotic the slaves themselves were—they were, after all, slaves). Feel free to post any follow on questions if you've got 'em!