Thailand's embattled weightlifting board has resigned in fresh fallout for the scandal-hit sport after an explosive documentary claiming misconduct and doping violations reverberated around the world.

German broadcaster ARD aired an undercover film earlier this month alleging a "culture of corruption" had been established in the Olympic sport, with prominent weightlifters rarely subjected to drugs tests and cash being taken by doping controllers to accept manipulated urine samples.

International Weightlifting Federation (IWF) president Tamas Ajan agreed to relinquish his duties for 90 days while an independent investigation is carried out.

But the undercover team also ensnared Thailand's weightlifting program, including an interview in which 2012 Olympic bronze medallist Siripuch Gulnoi (formerly Rattikan Gulnoi) admitted to using steroids when she was 18 years old -- something that could see her stripped of her prize.

The Thai Amateur Weightlifting Association said in a statement dated January 30 that the athlete was not aware she was being filmed and was "cheated" but that executive members of the board including its president resigned to "protect this national sport with our beloved country".

The statement admitted that in 2011 there was a doping scandal among Thai weightlifters but that it stemmed from provincial member clubs and those involved were sanctioned. Until recently weightlifting was one of Thailand's most prestigious sports, but its reputation cracked after nine Thais including two reigning Olympic champions were suspended after positive drug tests late last year.

Thailand then voluntarily banned itself from the Olympics and from hosting the September championships in the beach town Pattaya, which went on without any Thai athletes taking part. But the World Anti-Doping Agency has described the allegations related to Thailand in the film as "new and of great concern".

The documentary by journalists including Hajo Seppelt, who broke the story on Russia's state doping scandal, claimed that half of the 450 World Championship or Olympic medallists between 2008 and 2017 were not asked to undertake any doping tests.

A doctor for the Moldovan team was also caught on hidden camera explaining how urine samples could be manipulated. Beyond doping, the report accused the IWF of transferring $5 million in funding from the International Olympic Committee into two Swiss accounts overseen only by Ajan.

Hungarian Ajan, 81, has been at the IWF since 1976 serving 24 years as general secretary and the past 20 as president. He has led a very public effort to clean up the sport's image and claimed the documentary's allegations were unfounded.