"Pained to hear about the passing away of Rajya Sabha MP Shri Kalpataru Das. My condolences to his family. May his soul rest in peace," Modi tweeted.
"Shri Kalpataru Das was actively involved in social work & was extremely passionate about Odisha's progress," he added.
Das died here after a prolonged battle with cancer. He was 65.
Modi also condoled the demise of former Governor of Kerala and Bihar R S Gavai who passed away today after a prolonged illness at a private hospital here.
"We will always remember Shri RS Gavai's contribution towards welfare of poor & marginalised. My condolences to his family on his demise," he added.