"She has so many achievements in her life that a good book can be written on her, but I won't be justified in writing it. I will be more biased, " Raj, who married Shilpa in 2009, said.
"I think an outside writer should do it, " he added.
Shilpa, who started her career as a model in show business at the age of 16, ventured into acting in 1993 with "Baazigar" and was appreciated for her performances in films like "Dhadkan", "Rishtey" and "Phir Milenge".
She later garnered attention all over the world by winning Britain-based celebrity reality TV show "Big Brother" in 2007.
Meanwhile, on being asked about his plans to write his next book, Raj said: "It took me five years to write this book. Right now, I am relaxing and focusing on business and family."