UNITED STATES SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 4

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

( ) Check this box if no longer subject to Section 16.
Form 4 or Form 5 obligations may continue. See Instructions 1(b).

1. Name and Address of Reporting Person

     Mehmet C. Oz, M.D.
     177 Fort Washington Avenue, 7th Floor
     New York, NY  10032

2. Issuer Name and Ticker or Trading Symbol

    Siga Technologies, Inc. -- SIGA

3. IRS or Social Security Number of Reporting Person (Voluntary)

4. Statement for Month/Year

   May, 2001

5. If Amendment, Date of Original (Month/Year)

6. Relationship of Reporting Person(s) to Issuer (Check all applicable)

   (X) Director ( ) 10% Owner ( ) Officer (give title below) ( ) Other
   (specify below)


7. Individual or Joint/Group Filing (Check Applicable Line)

   (X) Form filed by One Reporting Person
   ( ) Form filed by More than One Reporting Person



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 Table I -- Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned                                                 |
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1. Title of Security     |2.      |3.    |4.Securities Acquired (A)         |5.Amount of        |6.Dir |7.Nature of Indirect       |
                         |  Transaction  |  or Disposed of (D)              |  Securities       |ect   |  Beneficial Ownership     |
                         |        |      |                                  |  Beneficially     |(D)or |                           |
                         |        |    | |                  | A/|           |  Owned at         |Indir |                           |
                         | Date   |Code|V|    Amount        | D |    Price  |  End of Month     |ect(I)|                           |
-----------------------------------------------------------------------------------------------------------------------------------|
                                                                            
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Common Stock, par value  |5/08/01  | P | |   12,500         | A |    (1)    |    25,000         |  D   |                           |
$0.0001                  |         |   | |                  |   |           |                   |      |                           |
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                         |         |   | |                  |   |           |                   |      |                           |
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                         |         |   | |                  |   |           |                   |      |                           |
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Reminder:  Report on a separate line for each class of  securities  beneficially
owned directly or indirectly.

* If the form is  filed  by more  than one  reporting  person,  see  Instruction
4(b)(v).

                                                                          (Over)
                                                                 SEC 1474 (7-96)
                                                                     Page 1 of 2





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 Table II -- Derivative Securitites Acquired, Disposed of, or Beneficially Owned                                                   |
-----------------------------------------------------------------------------------------------------------------------------------|
1.Title of Derivative |2.Con-  |3.   |4.    |5.Number of De |6.Date Exer|7.Title and Amount  |8.Price|9.Number    |10.|11.Nature of|
  Security            |version |Transaction | rivative Secu |cisable and|  of Underlying     |of Deri|of Deriva   |Dir|Indirect    |
                      |or Exer |     |      | rities Acqui  |Expiration |  Securities        |vative |tive        |ect|Beneficial  |
                      |cise    |     |      | red(A) or Dis |Date(Month/|                    |Secu   |Securities  |(D)|Ownership   |
                      |Price of|     |      | posed of(D)   |Day/Year)  |                    |rity   |Benefi      |or |            |
                      |Deriva- |     |      |               |Date |Expir|                    |       |ficially    |Ind|            |
                      |tive    |     |      |           | A/|Exer-|ation|   Title and Number |       |Owned at    |ire|            |
                      |Secu-   |     |    | |           | D |cisa-|Date |   of Shares        |       |End of      |ct |            |
                      |rity    |Date |Code|V|  Amount   |   |ble  |     |                    |       |Month       |(I)|            |
-----------------------------------------------------------------------------------------------------------------------------------|
                                                                            
-----------------------------------------------------------------------------------------------------------------------------------|
Common Stock Purchase |$2.94   |5/8/01| P  | | 12,500   |   |5/8/01|5/8/08|Common Stock|12,500| (1)  | 12,500     | D |            |
Warrant               |        |      |    | |          |   |      |      |            |      |      |            |   |            |
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Explanation of Responses:

(1) The Reporting Person purchased 12,500 shares of Common Stock and Warrants to
purchase 12,500 shares of Common Stock for an aggregate purchase price of
$25,000.


                                               /s/ Mehmet C. Oz, M.D.
                                               --------------------------------
                                               ** Signature of Reporting Person
                                                  Mehmet C. Oz, M.D.

                                               June 11, 2001
                                               -----------------
                                               Date

** Intentional misstatements or omissions of facts constitute Federal Criminal
   Violations.
   See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

Note:   File three copies of this Form, one of which must be manually signed.
        If space provided is insufficient, see Instruction 6 for procedure.

Potential persons who are to respond to the collection of information  contained
in this form are not  required to respond  unless the form  displays a currently
valid OMB Number.


                                                                 SEC 1474 (7-96)
                                                                     Page 2 of 2