Hiring Overseas: What Documents Do I Need Before Offering a Job to a Nigerian Applicant?

I have received one application from Nigeria. Since we have an opening for a data entry operator, and the applicant mentions having a good typing speed, I am considering hiring him for our BPO company. I would like to know which documents I need to collect from the applicant before finalizing his hiring for our office.

Why are you hiring a foreign national for such a clerical job? Is it in India or Nigeria? Normally, foreign nationals should be hired for specialized jobs and not for such roles.

Regards,

Actually, he is a student, and he is desperately searching for a job. Since he says that he has good typing speed, that is why I want to hire him for this job. It's his wish to join as a data entry operator, and his frequent calls are insisting that I hire him.

Regards,
Anamika