问题张某(男)和李某(女)系夫妻,后两人关系不和,两地分居。为防止离婚时李某分得房产,张某与生意伙伴赵某协商,将登记在其一人名下的两套房屋私下低价转让给赵某,双方签订了房屋买卖合同,并办理了不动产转移登记。张某和李某离婚后,李某得知了张某私下转移房产的行为,李某应当如何维护其房屋财产权益呢? The problem Zhang (male) and Lee (female) Department of husband and wife, the latter two relations and the two separated. In order to prevent the divorce, Lee got real estate, Zhang and business partners Zhao negotiations, will be registered in the name of two privately owned low-cost housing sold to Zhao, the two sides signed a contract for the sale of housing, and for real estate transfer Registration. After Zhang and Lee divorced, Lee learned Zhang private transfer of real estate behavior, Lee should be how to protect their housing property rights?