The Manhattan-based madam, Anna Gristina, arrested last week for running a high-end escort service was warned of an impending crackdown on escort services by her client Attorney General Elliot Spitzer in 2005. Kristin Davis, who ran a Manhattan call-girl service used by disgraced former Gov. Spitzer, said she shared a booker, Winnie Wong, with Gristina. Davis said she once spoke to Wong, who told her that Spitzer alerted Gristina to a 2005 investigation. Davis has taken and passed a lie detector test regarding her conversation with Wong in which Wong declared that Spitzer had given Gristina the warning.