35 U.S.C. § 295 : US Code - Section 295: Presumption: Product made by patented process

Search 35 U.S.C. § 295 : US Code - Section 295: Presumption: Product made by patented process

In actions alleging infringement of a process patent based on the
importation, sale, offer for sale, or use of a product which is
made from a process patented in the United States, if the court
finds -
(1) that a substantial likelihood exists that the product was
made by the patented process, and
(2) that the plaintiff has made a reasonable effort to
determine the process actually used in the production of the
product and was unable to so determine,
the product shall be presumed to have been so made, and the burden
of establishing that the product was not made by the process shall
be on the party asserting that it was not so made.