|They may have been corrupted by saving them to a faulty memory card, but I doubt they became infected whilst on your BlackBerry (not impossible but very rare).|
Antivirus software can give you "false positives" where a file is tagged as infected when in fact it's not -- a false alarm.
Some av software is worse than others at doing that, and when it occurs you need a "second opinion" - this means using a different antivirus to see how that deals with your pics. Try this free one: http://www.avast.com/free-antivirus...
Important - You must uninstall AVG entirely before any other antivirus can be installed.