Nicole Kidman kept "some of the placenta" after miscarrying Tom Cruise's child, it has been claimed.The Australian actress lost her unborn child in the early 90s and reportedly saved part of the ephemeral organ, which is rooted to the womb lining during pregnancy and delivered by expectant mothers as afterbirth, to prove Tom was the father.In controversial new book 'Tom Cruise: An Unauthorised Biography', author Andrew Morton claims: "Tom and Nicole did try to start a family but she sadly had a miscarriage. And because of all the questions over the father, she ordered that some of the placenta be saved in order to prove paternity - the fact that Tom Cruise was the father."Tom, who is a keen follower of Scientology, has previously revealed he is a fan of placentophagia - the practice of eating the placenta.Before current wife Katie gave birth to their daughter, Suri, Tom said: "I'm definitely going to eat the placenta. I thought that would be good. Very nutritious. I'm going to eat the cord and the placenta right there and then."Many mothers eat their placentas as they believe it is nutritiously beneficial and can help relieve post-natal depression. The Church of Scientology has branded Morton's tome "a bigoted, defamatory assault replete with lies", and threatened legal action.