N.Y.C. Admin. Code § 13-139: § 13-139 Prohibition upon trustees and employees.

Except as provided in this chapter, the trustees and employees of such board are prohibited from having any interest, directly or indirectly, in the gains or profits of any investment of the retirement system or as such, directly or indirectly, from receiving any pay or emolument for their services. The trustees and employees of such board, directly or indirectly, for themselves or as agents or partners of others, shall not borrow any of its funds or deposits or in any manner use the same except to make such current and necessary payments as are authorized by such board; nor shall any such trustee or employee become an indorser or surety or become in any manner an obligor for moneys loaned by or borrowed from such board.