New Zealand Flatworm

Found by my father-in-law in the garden. Then my mother-in-law remembers reading about New Zealand Flatworms - an import (obviously) that eats our native earthworms.

So a little research and we find that this is true. Some further research and I found an old Gardeners' World post that if any New Zealand Flatworms were found, to take a picture alongside a key (to gauge size) and send to the email address they provided. 

Now I just need to dig out that post again so that I can do as requested.