The Bollywood designer rejected claims from Ritu Kumar that she was involved in the project.
"That's not true at all. For the past two weeks, the workers in my unit have been painstakingly restoring Sharmila ji's old wedding lehenga that Bebo will wear for her nikaah on the 16th," Malhotra told Hindustan Times.
"I've put a lot of effort into carefully restoring the golden zardosi work. I don't know how someone else can claim to be doing it. That would not be right."
Responding to recent interviews where Kumar has spoken about working with Kapoor on her wedding look, Malhotra said: "I can't comment on that. Ritu ji is a senior designer."
Kumar is also said to have shared sketches of the outfits she claims to have designed for the event.
Malhotra earlier confirmed that he will be creating an outfit for Karisma Kapoor.
Posting on Twitter on Sunday (October 14), he wrote: "So in my workplace Kareena and Karisma's outfits: final finishing touches."
Kareena will marry long-term partner Saif Ali Khan at Pataudi Palace on October 16.