It is possible that there isn't a policy.
The lender may have details of the policy but it may not be such a good idea to write to ask "would you rather we paid you £60k or would you tell us about the policy". You may have to make enquiries there if you cannot find any other details. I would expect a policy to be paid by monthly payments although it's possible that it may have been paid together with another item (check the annual mortgage statement against the monthly payments for that).
It is not unusual for insurers to refuse to issue a new life insurance policy for an elderly/poorly person so I would expect the payments for any life or endowment policy to have been made for a number of years.