petitioners and Mr. Rishab Gupta, learned counsel for the respondent. 4. The award itself discloses, and this position is not disputed by Mr. Gupta, that the arbitrator was appointed by a letter dated 08.01.2018 by the respondent unilaterally. 5. The status of an award rendered by an arbitrator appointed by one of the parties, after the insertion of Section 12(5) in the Act by the Arbitration and Conciliation (Amendment) Act, 2015 is no longer res integra . The judgments of the Supreme Court in TRF Limited vs. Energo Engineering Projects Limited [(2017) 8 SCC 377] and Perkins Eastman Architects DPC & Anr. vs. HSCC (India) Limited [(2020) 20 SCC 760], make it clear that arbitration by an arbitrator appointed by one of the parties is impermissible. This principle has been followed in several judgments of this Court, to arrive at the conclusion that an award rendered by an arbitrator so appointed is null and void ab initio . The judgments of the Division Bench in Ram Kumar vs. Shriram Transport Finance Co. Ltd. [2022 SCC OnLine Del 4268] and Govind Singh vs. Satya Group Pvt. Ltd. [2023 SCC OnLine Del 37] are authorities for this proposition. In fact, this Court has held that even without an application for setting aside, an award rendered by an arbitrator appointed by one of the parties is unenforceable. Reference may be made to the Division Bench decisions in Kotak Mahindra Bank Ltd. v. Narendra Kumar Prajapat [2023 SCC OnLine Del 3148] and Babu Lal v. Cholamandalam Investment & Finance Co. Ltd. [2023 SCC OnLine Del 7239]. The judgment in Kotak Mahindra [ supra ] was carried to the Supreme Court, which rejected Special Leave to Appeal [by order dated 12.12.2023 in Special Leave to Petition under Diary No. 47322/2023].