User unable to access sharepoint portal

Hi,

There's a user who had left project but rejoined. So, his account was created again in the active directory.

But the user is not able to access the sharepoint portal now.

There's no entry for this user in the user information list at - http://<site>/_layouts/people.aspx/MembershipGroupID=0

Please suggest how to enable access for this user.

Thanks.