If the battery looks as shown, or as the originals that came with the Defy, then he will probably be genuine. Who has got a different lookout end detail with clear print image or other lack of security features, should complain to the merchants.
The originals was with me to exchange 3 years use, but had subsided lately arg. How do I now realized were missing probably already more than 50% of capacity. But I think the security aspect for at least as important as the capacity.