SAR - BRITISH BIOTECH PLC

    Amvescap PLC


FORM SAR 3




Lodge with Company Announcements Office and the Panel.  A copy must also be sent to the company
 the shares of which are acquired.

                                                            Date of disclosure 30 SEPTEMBER 2003

                         DISCLOSURE UNDER RULE 3 OF THE RULES GOVERNING
                          SUBSTANTIAL ACQUISITIONS OF SHARES ("SARs")

Date of acquisition  29 SEPTEMBER 2003

Acquisition in ......... BRITISH BIOTECH PLC ....... (name of company)

      Class of voting shares       Number of shares/rights      If rights over shares
      (eg ordinary shares)         over shares acquired         acquired, as opposed
                                                                to the shares
                                                                themselves, specify
   (1)                                                          nature of rights

               ORDINARY 5P                              469,199                               -

      Resultant total holding      Resultant total holding      Total percentage
      of voting shares (and %      of rights over shares
      of total voting shares       (and % of total voting
   (2)in issue)                    shares in issue)

                36,897,713 (27.17%)                           -              36,897,713 (27.17%)

   (3)Party making disclosure................ AMVESCAP PLC

      (a)  Name of person acquiring shares or rights over shares  DISCRETIONARY
                                                    MANAGED CLIENTS OF AMVESCAP
   (4)     and, if different, beneficial owner

      (b)  Names of any other persons acting by
           agreement or understanding (see SAR 5)


Signed, for and on behalf of the party named in (3) above...... A. TULLY

(Also print name of signatory)............ ANGELA TULLY

Telephone and extension number........... 020 7065 3652

Note. Under SAR 5, the holdings of and acquisitions by persons acting by
agreement or understanding must be aggregated and treated as a holding of or
acquisition by one person.  Note 3 on SAR 5 requires persons who must aggregate
holdings to disclose certain disposals.


For full details of the SARs disclosure requirements, see Rules 3 and
5 of the SARs. If in doubt, contact the Panel on Takeovers and
Mergers, Monitoring Section. Tel. No: 020 7638 0129.
Email:[e-mail]