If this is Term Insurance (the type where the term is fixed at the start of the contract to say 10 or 20 years), there is a premium to be paid each month to maintain the policy. Who is paying the premium - him presumably.
I don't believe the contract has changed as a result of the divorce - each of you is named as the beneficiary in the event the other dies. Clearly this should have thought of as part of the financial separation when you divorced. But if it is Term Insurance and he's paying it, he can cancel the policy at any time and cease paying the premiums.