Press Release

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

Disclosure of Significant Shareholdings - 22 October 2007

Osmetech PLC (“Osmetech” or “the Company”) announces that on 19 October 2007 it was notified that Efficacy Capital Ltd has increased its shareholding in Osmetech to 24,525,000 Ordinary 0.1p shares.

This represents 12.08% 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 21.585,000 shares representing 10.63% of Osmetech’s issued share capital.

FMG Special Opportunity Fund which holds 2,940,000 shares representing 1.45% of Osmetech’s issued share capital.

For further information:

Madano Partnership	+44 (0)20 7593 4000
Mark Way / Graham Moonie