Former Union Minister P Chidambaram, who is in Tihar jail in Delhi since September 5 in INX media case, is in "great spirits", his son Karti said today after visiting him this morning at the jail. The 74-year-old Congress leader was arrested by a three-member team of the Enforcement Directorate today after he was questioned for nearly an hour at Delhi's Tihar Jail in the money-laundering case.