By, Vasu Manchanda
The Indian Evidence Act, 1872 entails the burden of proof and its onus on the plaintiff. According to Section 101 of the Indian Evidence Act, 1872, the burden to prove the existence of the claimed fact is on the person who asserts it (plaintiff).
In the absence of any exception created by law, the burden of proof falls on the person who has asserted any fact or made any claim on the basis of which her legal right is violated or any legal liability is accrued. For example- Ms. X desires the court to give a judgment that Ms. Y is in adverse possession of the land belonging to her, to which Ms. Y denies. The burden to prove that Ms. Y is indeed in adverse possession of the land is on Ms. X.
Burden of proof in patent infringement suit
On the same premise, in a patent infringement suit, the burden of proof lies on the plaintiff (patentee). It is the plaintiff (patentee) who has to prove that the alleged patent has been breached, by adducing material evidence. Nevertheless, if the matter in controversy of the alleged patent is a process and the plaintiff (patentee) can establish that the contravened product is similar to the product legitimately obtained by the patented process, the burden of proof may move to the defendant (infringer) to prove that the procedure adopted by her is not the same as the patented process.
In Farbeweke Hoechst Aktiengesellschaft Vormals Meister Lucius & Bruning, A Corporation v. Unichem Laboratories and others, it was held by the Hon’ble High Court of Bombay that the burden of proof in cases where the patent is a process is based on Section 106 of the Evidence Act, 1872, according to which, when a fact is especially within the knowledge of a person, the burden of proving the fact is on her. Thus, in case the process by which the product is attained is especially within the knowledge of the defendant (infringer), it is preposterous for the patentee to have the exact knowledge of how the infringed product has been attained by the infringer. Therefore, the burden to prove that the process adopted to make the infringed product is not the same as the patented process lies on the defendant (infringer).
In Communications Component Antenna Inc. v. ACE Technologies Corporation and others, it was held by Justice Prathiba M. Singh that if the defendant (infringer) retains relevant data and crucial information that constitutes easily obtainable evidence from the court, an unfavourable inference can be drawn against it. It was further held that once the plaintiff (patentee) ostensibly proves patent process infringement, the burden falls on the defendant (infringer) to refute the same.
In addition to Section 106 of the Indian Evidence Act, 1872, Section 104A of the Patents Act, 1970, also deals with burden of proof pertaining to process patent. It provides that in a patent infringement suit that involves a process for obtaining a product, the defendant (alleged infringer) may be directed by the court to prove that the process adopted by her to obtain the product that is similar to the product obtained from the patented process, is actually different from the process patented by the plaintiff (patentee).
In Shogun Organics Ltd v. Gaur Hari Guchhait and others, the plaintiff filed a suit for permanent injunction restraining the defendants from contravening its process patent. It alleged that Solex Chemicals Pvt. Ltd. and other parties (defendants) were using its patented technology of making an insecticide. It established that it was granted the patent in 2009 and thereafter, the defendants sold some products with the inclusion of some substances peculiar to the patented process. Thus, the burden fell on the defendants to disprove that the process used by them was identical to the patented process.
The plaintiff contended that its patent had novelty and relied on the registration of its product with the Central Insecticides Board and Registration Committee while the defendants relied on the registration of their product and contended that the process was within public knowledge.
Further, the defendants neither disclosed their process nor proved that the product obtained by them had distinct properties or ingredients from the product obtained by the patented process. As they adduced no evidence, the Hon’ble High Court of Delhi drew unfavourable inference against them and held them to have infringed the patent process.
Therefore, with the help of the above-mentioned judgments, it can be inferred that in cases of process patents, once the plaintiff (patentee) establishes that the infringed product is identical to the plaintiff’s product obtained by the patented process, the burden of proof falls on the defendant (infringer) to prove that the process adopted by it is different from the patented process.
 The Indian Evidence Act, 1872, s. 101
 AIR 1969 Bom 255
 The Indian Evidence Act, 1872, s. 106
 2019 SCC OnLine Del 9123
 The Patents Act, 1970, s. 104A
 2019 SCC OnLine Del 9653 : (2019) 263 DLT 516
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