And what number would that be - 3? 300? 3000? And from what source did you "hear" this?
Here's a place to start. Domestic Violence in Religious Congregations: Implications for Social Work Practice
Quote from the above website: "Social workers often face special challenges when addressing conservative Christian groups on difficult social issues such as domestic violence. The literature offers complex and sometimes conflicting data concerning religion and domestic violence. Studies report that conservative Christian men do not abuse their partners more than other denominations (Brinkerhoff, Grandin, & Lupri 1992) and regular attendance in religious services is inversely associated with perpetration of domestic violence (Ellison & Anderson, 2001). However, men who hold more conservative theological views than their partners are especially likely to perpetrate domestic violence (Ellison & Anderson, 2001). Little empirical work has been done, however, specifically on how religiosity may influence help-seeking behaviors. This study builds on existing literature by offering findings that help clarify the relationship between religiosity and help-seeking behaviors among religiously affiliated people."
(snip)
"In this sample of church attendees, holding more conservative religious views is associated with engaging in fewer help-seeking activities. While victimization rates vary little across religiosity categories, help-seeking activities vary significantly. Conservative respondents were as likely to be victimized as their liberal counterparts; however, they were less likely to seek help on a number of variables. These findings suggest a need for social workers to address barriers to help-seeking among people holding more conservative religious views. Social workers need to understand the restraints and barriers to help-seeking among all at-risk groups and design interventions that hold appeal across the spectrum of religiosity. "
This might be the real crux of the problem: People who are religiously conservative are less likely to seek outside help in dealing with domestic violence issues. One may presume that such people are more likely to take matters into their own hands for a solution to their distress, whether the vicitm is male or female.
The sad thing though is that the studies show that religious men are as likely to beat their wives as non-religious men. Christians are also just as likely, if not more likely, to get divorced as non-Christians. If this is the case, it's not exactly a good selling point for being religious, is it?