Cannot create worker as person number already exists

Summary:

Cannot create worker as person number already exists, reason being due to some mistake user canceled work relationship and now trying to create employment of same person person again.

Content (required):

Cannot create worker as person number already exists, reason being due to some mistake user canceled work relationship and now trying to create employment of same person person again.

Since person record is exist and its not visible from UI therefore new person screen not allowing us to create person with same person number, person number is important as its been allotted to employee. How to create employment record for such person.