Cal. Civ. Code § 1695.12
In any transaction in which an equity seller purports to grant a residence in foreclosure to an equity purchaser by any instrument which appears to be an absolute conveyance and reserves to himself or herself or is given by the equity purchaser an option to repurchase, such transaction shall create a presumption affecting the burden of proof, which may be overcome by clear and convincing evidence to the contrary that the transaction is a loan transaction, and the purported absolute conveyance is a mortgage; however, such presumption shall not apply to a bona fide purchaser or encumbrancer for value without notice of a violation of this chapter, and knowledge on the part of any such person or entity that the property was "residential real property in foreclosure" shall not constitute notice of a violation of this chapter. This section shall not be deemed to abrogate any duty of inquiry which exists as to rights or interests of persons in possession of the residential real property in foreclosure.
Ca. Civ. Code § 1695.12