Press Release

Osmetech PLC (“Osmetech” or “the Company”) (AIM:OMH) announces that it was notified on 23 December 2009 that, following the placing at 2.05p per share announced on 21 December 2009, FMR LLC has a total interest of 147,133,039 ordinary 0.1p shares in the Company which represents approximately 9.01% of the issued share capital of the Company.

The total number of issued ordinary 0.1p shares is 1,633,443,351. Osmetech does not hold any ordinary shares in Treasury. Therefore, the total number of voting rights in Osmetech is 1,633,443,351.