The mystery substance recently found in two suspicious packages is expected to be identified in the next few days.
The packages were intercepted at Isle of Man Post eight days ago, and police are waiting for the results of tests.
The items seemed to originate from Algeria and were addressed to finance firms on the Island.
Inspector Derek Flint says, given the similarity to past incidents, they are not overly-concerned.
However, he is advising people to remain vigilant:
Researching your Manx family history can be a very interesting and rewarding hobby. Trace your roots in the Isle of Man with our helpful of guide.
