Press Release

Osmetech plc ('Osmetech' or the 'Company')

Disclosure of Significant Shareholdings - 27 September 2007

Osmetech PLC (“Osmetech” or “the Company”) announces that on 27 September 2007 it was notified that Efficacy Capital Ltd has increased its shareholding in Osmetech to 20,390,000 Ordinary 0.1p shares.

This represents 10.04% of the Company’s issued share capital of 203,014,972 Ordinary shares.

The shareholding is held in two entities:

Efficacy Biotech Master Fund which holds 18,650,000 shares representing 9.19% of Osmetech’s issued share capital.

FMG Special Opportunity Fund which holds 1,740,000 shares representing 0.86% of Osmetech’s issued share capital.