(1) Without prejudice to any other right to discovery, the Attorney General may, in forfeiture proceedings administer interrogatories to and obtain discovery of documents from a defendant with respect to a matter or document that may prove that a person is an alien or to discover land held by an alien.
(2) It is not a valid ground, to refuse to answer an interrogatory or to refuse to disclose or produce any document, that the answer or document may expose a person to prosecution under this Act.
(3) In the prosecution of a person under this Act, the fact that the person has disclosed a matter in answer to an interrogatory administered under this section and disclosed or produced a document in compliance with an order for discovery obtained under this section is not admissible in evidence.