Google picked up the following URL and ranked it:
http://www.example.com/yyy/zzz-99.php?item_id=99&sort=1 (the item_id=99 part should not be there).
Since I picked up the error and fixed it, I have added the following line to my htaccess:
RedirectPermanent /yyy/zzz-99.php?item_id=99&sort=1 http://www.example.com/yyy/zzz-99.php?&sort=1
However that redirect does not work. Any clue on what i am doing wrong?