India's most popular professional wrestler, Dara Singh, passed away Thursday morning at the age of 83 due to cardiac arrest.

Singh wrestled internationally from the 1940's through 1983, when he retired. He went on to have a successful movie career in India, and was inducted into the Wrestling Observer Newsletter Hall of Fame in 1996.

William Regal commented on Singh's passing on his Twitter account, writing, "Very sad indeed to hear of the passing of the legendary Wrestler Dara Singh.I wrestled for him in India in 1992.A truly elegant gentleman."

Jim Ross also commented on his passing, writing on his Twitter, "Legit legend. Big rival of Lou Thesz. RIP."

Ryan contributed to this article. Follow Raj Giri on Twitter at @RajGiri_303. Got a news tip or correction? Send it to us by clicking here.