find /path/to/check  -type f -print0 | xargs -0 md5sum > /tmp/hashs.txt
cat /tmp/hashs.txt | awk '{print $1}' | sort | uniq -c | grep -v "1 " | awk '{print $2}' > /tmp/duped.txt
for h in `cat /tmp/duped.txt`; do 
  grep $h /tmp/hashes.txt; 
done