Exhibit 4

                                LOCK UP AGREEMENT



RBS Mezzanine Limited
   As Arranger and Agent
135 Bishopsgate
London  EC2M 3UR

         Re:      INVERNESS MEDICAL INNOVATIONS, INC. (THE "COMPANY")

Ladies and Gentlemen:

         Reference is hereby made to that certain Mezzanine Loan Agreement by
and among the Company, Inverness Medical Switzerland GmbH, certain banks, RBS
Mezzanine Limited, as arranger and agent ("RBS"), and certain other parties (the
"Mezzanine Loan Agreement"). Each of the undersigned is an owner of record and
beneficially of certain shares of the common stock, $.001 par value per share,
of the Company ("Common Stock") and securities convertible into or exchangeable
or exercisable for Common Stock. It is a requirement of the Mezzanine Loan
Agreement that the undersigned execute and deliver this agreement. The
undersigned recognize that the Mezzanine Loan Agreement will benefit the Company
by, among other things, raising additional capital for its operations. The
undersigned acknowledge that RBS and the other banks party to the Mezzanine Loan
Agreement are relying on the representations and agreements of the undersigned
contained in this agreement in entering into the Mezzanine Loan Agreement and
advancing funds to the Company thereunder.

         This agreement shall remain in effect until the Company has made full
and final payment of all amounts due under the Mezzanine Loan Agreement (the
"Termination Date"). For the avoidance of doubt, the Company's obligations under
the common stock purchase warrants issued in connection with the Mezzanine Loan
Agreement shall not be deemed to represent amounts due under the Mezzanine Loan
Agreement.

         In consideration of the foregoing, and for good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
undersigned hereby agree that the undersigned will not, without the prior
written consent of RBS (which consent may be withheld in its sole discretion),
directly or indirectly, sell, offer, contract or grant any option to sell
(including without limitation any short sale), pledge, transfer, or otherwise
dispose of (collectively, "Sell") any shares of Common Stock, options or
warrants to acquire shares of Common Stock, or securities exchangeable for or
convertible into shares of Common Stock (collectively, "Company Securities")
currently or hereafter owned either of record or beneficially by the undersigned
during the period beginning on the date of this agreement and ending on December
20, 2004. During the period from December 20, 2004 through the Termination Date,
the undersigned will not Sell Company Securities representing more than an
aggregate of twenty five percent (25%) of the total number of shares of Common
Stock represented by all of the Company Securities owned either of record or




RBS Mezzanine Limited,
   As Arranger and Agent
December 20, 2001
Page 2

beneficially by the undersigned on December 20, 2004, and will not Sell more
than an aggregate of 10% of such number in any twelve (12) month period,
provided, however, that the undersigned will not Sell any Company Securities at
any time that the Company is in default under the Mezzanine Loan Agreement. The
undersigned consent to the entry of stop transfer instructions with the
Company's transfer agent and registrar against the transfer of Company
Securities held by the undersigned except in compliance with the foregoing
restrictions. The foregoing restrictions shall not be deemed to prohibit the
undersigned from exercising any option or warrant to purchase Company Securities
or from exercising the exchange or conversion rights of any Company Security,
provided, however, that the Company Securities received by the undersigned as a
result of any such exercise shall remain subject to the provisions of this
agreement.

         Each of the undersigned hereby represents and warrants that he or it
has full power and authority to enter into this agreement. This agreement is
irrevocable and will be binding on the undersigned and the respective successors
and assigns of the undersigned.

Dated:  December 20, 2001

                                                 ZWANZIGER FAMILY VENTURES, LLC


/s/ Ron Zwanziger                                By: /s/ Ron Zwanziger
-----------------------------                    ------------------------------
Ron Zwanziger                                    Name:
                                                 Title:

ACCEPTED AND AGREED TO:

RBS Mezzanine Limited


By: /s/ [Authorized Representative]
    ---------------------------------
    Name:
    Title:


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