Jared Kushner has turned over documents in recent weeks to special counsel Robert Mueller as investigators have begun asking in witness interviews about Kushner's role in the firing of FBI Director James Comey, CNN has learned.

Mueller's investigators have expressed interest in Kushner, President Donald Trump's son-in-law and a White House senior adviser, as part of its probe into Russian meddling, including potential obstruction of justice in Comey's firing, sources familiar with the matter said.