N.Y. Exec. Law § 296-D
It shall be an unlawful discriminatory practice for an employer to permit unlawful discrimination against non-employees in its workplace. An employer may be held liable to a non-employee who is a contractor, subcontractor, vendor, consultant or other person providing services pursuant to a contract in the workplace or who is an employee of such contractor, subcontractor, vendor, consultant or other person providing services pursuant to a contract in the workplace, with respect to an unlawful discriminatory practice, when the employer, its agents or supervisors knew or should have known that such non-employee was subjected to an unlawful discriminatory practice in the employer's workplace, and the employer failed to take immediate and appropriate corrective action. In reviewing such cases involving non-employees, the extent of the employer's control and any other legal responsibility which the employer may have with respect to the conduct of the person who engaged in the unlawful discriminatory practice shall be considered.
N.Y. Exec. Law § 296-D