tedster - 1:22 am on Mar 28, 2012 (gmt 0) [edited by: tedster at 1:34 am (utc) on Mar 28, 2012]
The possibility of competitors sabotaging a link profile is currently getting a lot of buzz. In my experience, the best defense is a strong, natural link profile. Saboteurs cannot take down a strong site. But if the site is already wobbly, has been using edgy link building tactics, etc - then I think it may be more vulnerable today.
If you cannot remove those questionable backlinks, and you are 100% certain that no one authorized to work on your site has placed them, you can reply to the Google message with full details of your discovery. I do know of cases where this kind of problem was reversed.
Also note - the link profile area is not part of Panda - so don't get into calling everything "Panda" - it just isn't the case.
[edited by: tedster at 1:34 am (utc) on Mar 28, 2012]