In the event a contract requires a procedure to ensure that employees do not engage in trafficking of persons, procurement of sexual acts, or use of forced labor in performance of the contract, the Contracting Officer shall obtain in writing an affirmative assurance from the PI/PD that s/he has received a copy of this policy and the contract clause and that s/he shall exercise control over the project to prevent such actions and shall not knowingly contract with, purchase goods or services from, or collaborate with persons who will engage in activities prohibited hereunder in performance of the contract.