Asian Games gold medal-winning former boxer Dingko Singh died on Thursday after a long battle with liver cancer.
He was 42 and had been fighting the disease since 2017.
Tokyo Olympic-bound Mary Kom mourned the death on social media, calling Dingko her hero.
"You were a true hero of our nation. You leave but your legacy will live among us. RIP," wrote Mary on Twitter.
"I'm deeply saddened by the demise of Shri Dingko Singh. One of the finest boxers India has ever produced, Dinko's gold medal at 1998 Bangkok Asian Games sparked the Boxing chain reaction in India. I extend my sincere condolences to the bereaved family. RIP Dinko," Sports Minister Kiren Rijiju tweeted.
The Manipur-based former boxer endured a long battle with cancer and even fought COVID-19 last year.
"My sincerest condolences on this loss May his life's journey & struggle forever remain a source inspiration for the upcoming generations. I pray that the bereaved family finds the strength to overcome this period of grief & mourning #dinkosingh," tweeted India's first Olympic-medallist in boxing Vijender Singh.
Dingko won the Asian Games gold in 1998 and was bestowed the Arjuna award the same year. In 2013, he was honoured with the Padma Shri for his contribution to the sport.
Dingko, who was employed with Navy, had taken to coaching after hanging up his gloves.
