The Iranian clinched gold at London 2012 and Rio 2016, breaking the men's over 107 kilograms category world record with a lift of 310kg at the latter Games. 

He also topped the podium at the last three Asian Para Games in Guangzhou, Incheon and Jakarta. 

Rahman passed away at the Nabi-akram Hospital in West Azerbaijan province after suffering a heart attack, as reported by Tehran Times. 

He had been preparing to earn his third consecutive Paralympic gold medal at Tokyo 2020, having been part of a visual campaign promoting the Games last year. 

International Paralympic Committee President Andrew Parsons led the tributes to Rahman.

"The whole Paralympic Movement is deeply saddened to learn of the passing of Siamand Rahman," he said. 

"As the world’s strongest Paralympian, he made global headlines at Rio 2016 when he became the first Para athlete to lift over 300kg. 

"Few will forget that phenomenal performance which marked a landmark in the history of Paralympic sport.

"Siamand was a pioneer for his sport, an inspiration for many in his home country Iran and around the world, and a fantastic ambassador for the Paralympic Movement. 

"He was also a wonderful human being, a gentle giant and one of the friendliest people you could ever meet.

"The thoughts and deepest condolences of the whole IPC, World Para Powerlifting and the Paralympic Movement are with Siamand’s family, friends and loved ones at this difficult time. 

"Our prayers are also with our friends at the Iranian National Paralympic Committee.

"Sadly, today we have lost a true Paralympic great.”

Asian Paralympic Committee President Majid Rashed was another to offer his condolences. 

"Siamand's many achievements demonstrate what a superb athlete he was, but away from the competition arena he was a lovely, gentle man who always had time for everyone. 

"He has gone too soon and will be much missed by us all."