diff --git a/CHANGES.txt b/CHANGES.txt
index 9930e10..41e0355 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -4,6 +4,10 @@ Changelog
 2.0b1 (Unreleased)
 ------------------
 
+- Provide a filter_callback option to the migration view, so that a custom
+  policy for which comments get migrated can be implemented.
+  [davisagli]
+
 - Fixed RoleManager import to avoid deprecation warning on Zope 2.13.
   [davisagli]
 
diff --git a/plone/app/discussion/browser/migration.py b/plone/app/discussion/browser/migration.py
index 8bc5cc6..0af9fb3 100644
--- a/plone/app/discussion/browser/migration.py
+++ b/plone/app/discussion/browser/migration.py
@@ -19,7 +19,7 @@ class View(BrowserView):
     """Migration View
     """
 
-    def __call__(self):
+    def __call__(self, filter_callback=None):
 
         context = aq_inner(self.context)
         out = []
@@ -44,7 +44,7 @@ class View(BrowserView):
             context.plone_log(msg)
             out.append(msg)
 
-        def migrate_replies(context, in_reply_to, replies, depth=0):
+        def migrate_replies(context, in_reply_to, replies, depth=0, just_delete=0):
             # Recursive function to migrate all direct replies
             # of a comment. Returns True if there are no replies to
             # this comment left, and therefore the comment can be removed.
@@ -52,34 +52,46 @@ class View(BrowserView):
                 return True
 
             for reply in replies:
-
+                
                 # log
                 indent = "  "
                 for i in range(depth):
                     indent += "  "
                 log("%smigrate_reply: '%s'." % (indent, reply.title))
 
-                # create a reply object
-                comment = CommentFactory()
-                comment.title = reply.Title()
-                comment.text = reply.text
-                comment.creator = reply.Creator()
+                should_migrate = True
+                if filter_callback and not filter_callback(reply):
+                    should_migrate = False
+                if just_delete:
+                    should_migrate = False
 
-                comment.creation_date = datetime.fromtimestamp(
-                    reply.creation_date)
-                comment.modification_date = datetime.fromtimestamp(
-                    reply.modification_date)
+                new_in_reply_to = None
+                if should_migrate:
+                    # create a reply object
+                    comment = CommentFactory()
+                    comment.title = reply.Title()
+                    comment.text = reply.text
+                    comment.creator = reply.Creator()
+                
+                    email = reply.getProperty('email', None)
+                    if email:
+                        comment.author_email = email
 
-                comment.reply_to = in_reply_to
+                    comment.creation_date = datetime.fromtimestamp(
+                        reply.creation_date)
+                    comment.modification_date = datetime.fromtimestamp(
+                        reply.modification_date)
 
-                if in_reply_to == 0:
-                    # Direct reply to a content object
-                    new_in_reply_to = conversation.addComment(comment)
-                else:
-                    # Reply to another comment
-                    comment_to_reply_to = conversation.get(in_reply_to)
-                    replies = IReplies(comment_to_reply_to)
-                    new_in_reply_to = replies.addComment(comment)
+                    comment.reply_to = in_reply_to
+
+                    if in_reply_to == 0:
+                        # Direct reply to a content object
+                        new_in_reply_to = conversation.addComment(comment)
+                    else:
+                        # Reply to another comment
+                        comment_to_reply_to = conversation.get(in_reply_to)
+                        replies = IReplies(comment_to_reply_to)
+                        new_in_reply_to = replies.addComment(comment)
 
                 self.total_comments_migrated += 1
 
@@ -88,7 +100,9 @@ class View(BrowserView):
                 no_replies_left = migrate_replies(context,
                                                   new_in_reply_to,
                                                   talkback.getReplies(),
-                                                  depth=depth+1)
+                                                  depth=depth+1,
+                                                  just_delete=not should_migrate)
+
                 if no_replies_left:
                     # remove reply and talkback
                     talkback.deleteReply(reply.id)
diff --git a/plone/app/discussion/tests/test_migration.py b/plone/app/discussion/tests/test_migration.py
index 6a3a150..d9bd8d3 100644
--- a/plone/app/discussion/tests/test_migration.py
+++ b/plone/app/discussion/tests/test_migration.py
@@ -167,6 +167,44 @@ class MigrationTest(PloneTestCase):
         talkback = self.discussion.getDiscussionFor(self.doc)
         self.assertEquals(len(talkback.getReplies()), 0)
 
+    def test_migrate_nested_comments_with_filter(self):
+        # Create some nested comments and migrate them.
+        # But use a filter that filters the top-level comment.
+        # All the comments should be removed, but not migrated.
+        #
+        # self.doc
+        # +- First comment
+        #    +- Re: First comment
+
+        talkback = self.discussion.getDiscussionFor(self.doc)
+
+        # First comment
+        talkback.createReply(title='First comment',
+                             text='This is my first comment.')
+        comment1 = talkback.getReplies()[0]
+        talkback_comment1 = self.discussion.getDiscussionFor(comment1)
+
+        # Re: First comment
+        talkback_comment1.createReply(title='Re: First comment',
+                                      text='This is my first reply.')
+        comment1_1 = talkback_comment1.getReplies()[0]
+        talkback_comment1_1 = self.discussion.getDiscussionFor(comment1_1)
+
+        self.assertEquals(len(talkback.getReplies()), 1)
+        self.assertEquals(len(talkback_comment1.getReplies()), 1)
+        self.assertEquals(len(talkback_comment1_1.getReplies()), 0)
+
+        def deny_comments(reply):
+            return False
+
+        # Call migration script
+        self.view(filter_callback=deny_comments)
+
+        # Check migration
+        conversation = IConversation(self.doc)
+        self.assertEquals(conversation.total_comments, 0)
+        talkback = self.discussion.getDiscussionFor(self.doc)
+        self.assertEquals(len(talkback.getReplies()), 0)
 
 def test_suite():
     return unittest.defaultTestLoader.loadTestsFromName(__name__)