Under Section 104A(1) of the Patents Act, 1970, the court may direct the defendant to prove that the…

Clause (a) of section 104A(1) applies where "the subject matter of the patent is a process for obtaining a new product". For a known product the burden shifts only under clause (b), on a substantial likelihood that the identical product was made by the process and the patentee's failure, despite reasonable efforts, to find the process actually used.