CA Civ Proc Code Section 873.690

(a)

The following persons shall not purchase property sold in the action directly or indirectly:

(1)

The referee.

(2)

The attorney of a party.

(3)

The guardian or conservator of a party, unless for the benefit of the ward or conservatee.

(b)

All sales contrary to this section are void except that a sale to a bona fide purchaser following a sale contrary to this section shall not be disturbed.