Siddharth, who was Bedi's child with first wife Protima, had a long history of schizophrenia and committed suicide at the age of 26.
"On this day, I miss my brilliant and sensitive son, Siddharth, Carnegie Mellon grad, who left us in the prime of his youth," the 66-year-old actor posted on Twitter today.
His other two children, Pooja and Adam, are Bollywood actors. Pooja has acted in films like "Jo Jeeta Wahi Sikandar" and Adam made his debut with 2006 thriller "Hello Kaun Hai".