Cal. Probate Code - PROB § 2616. Section 2616.
(a)
A petition may be filed under this article by any one or more of the following:
(1)
The guardian or conservator.
(2)
The ward or conservatee.
(3)
A creditor or other interested person, including persons having only an expectancy or prospective interest in the estate.
(b)
Upon the filing of a petition under this article, the court may order that a citation be issued to a person to answer interrogatories, or to appear before the court and be examined under oath, or both, concerning any of the following allegations made in the petition:
(1)
The person has wrongfully taken, concealed, or disposed of property of the ward or conservatee.
(2)
The person has knowledge or possession of any of the following:
(A)
A deed, conveyance, bond, contract, or other writing that contains evidence of or tends to disclose the right, title, interest, or claim of the ward or conservatee to property.
(B)
An instrument in writing belonging to the ward or conservatee.
(3)
The person asserts a claim against the ward or conservatee or the estate.
(4)
The estate asserts a claim against the person.
(c)
If the citation requires the person to appear before the court, the court and the petitioner may examine the person under oath upon the matters recited in the petition. The citation may include a requirement for this person to produce documents and other personal property specified in the citation.
(d)
Disobedience of a citation issued pursuant to this section may be punished as a contempt of the court issuing the citation.