The order of Justice N K Sanghi came on a petition filed by D S Guru, former Principal Secretary to Punjab Chief Minister and the SAD-BJP candidate from the seat, who had lost out to Sadiq in the January 2012 assembly polls.
The court held that Sadiq was a Muslim and as per Scheduled Caste order 1950, issued under Constitution, people belonging to Hindu, Sikh or Buddhist religions only can avail benefits of the reserved quota.
"This is a historic judgement which clarifies that benefits for SCs can be availed only by Hindus, Sikhs and Buddhists and not by Muslims and Christians," Guru's counsel Satya Pal Jain said.
"The caste system is prevalent only in Hindus, Sikhs and Buddhists and not in Muslims and Christians," he said.