This confusion came into my mind after watching Ekta Kapoor's 'Kahani Mahabharat Ki..' TV serial.
I saw this story that Rishi Vyasa was the biological father of Dhitarashtra and Pandu, or something like that. Is this true? What is the story behind the birth of Dhritarashtra and Pandu? Or was that Vidur who was the son of Vyasa?