Profiles missing from import still showing up in select people and group webpart dialog

We have created a new domain in our company and "migrated" our users to it. After a while (1-2 months), the old domain controllers were deleted, so all users from these old domains are not sync anymore and show up in the CA when I search for them selecting "Profiles missing from import". However, they still show up in the Select People and Group Webpart dialog, so when someone search for a name, they see at least two options (old domain user, new domain user). Is there a way to eliminate the old DC entries from the search?

Regards,

Samuel Souza