Perhaps I could make a first stab at that.
I think this comes back to the original concerns that Parliament had about DNA in the hands of the police. Going back to the very beginning of the DNA debates back in 1998, and before that, there was certainly a lot of debate around how much information the police would be allowed to have concerning DNA taken from citizens--how it was kept, how it was transmitted. The end result was a very restrictive regime about the keeping, using, and transmitting of information that the police had from DNA that is kept in a database nationally.
I believe that's why we're seeing restrictions imposed by the legislation on what can be reported abroad and shared with respect to DNA specifically.