A three-year investigation into the International Weightlifting Federation (IWF) has uncovered cases of suspected urine substitution and "doppelgangers" being used to impersonate athletes, the World Anti-Doping Agency (WADA) said on Thursday.
Eighteen weightlifters from six countries are suspected of giving manipulated samples, WADA said, adding that the cases of urine substitution would be forwarded to the International Testing Agency (ITA).
WADA said it found evidence of "doppelgangers" being used to impersonate athletes during the sample collection process.
The discovery was part of multiple and ongoing WADA probes that began in 2017, including Operation Arrow, a covert investigation into the practice of urine substitution at the point of collection.
Other branches of the investigation included Operation Outreach, which looked into accusations that a high-ranking member of the IWF was paid to protect Russian athletes from detection, and Operation Heir, which looked into allegations of an organised doping and a protection scheme operating within Romanian weightlifting.
The IWF did not immediately respond to a request for comment.
"WADA is appalled by what its Intelligence and Investigations Department has uncovered in this investigation," WADA president Witold Banka said in a statement.
"For too long, clean weightlifters have had to deal with an entrenched culture of doping in their sport, where the promotion of fear ensured that the truth remained hidden and that those who wanted to do the right thing were isolated."
An independent investigation into the IWF conducted earlier this year by Canadian law professor Richard McLaren found widespread corruption within the organisation, including doping cover-ups with fines paid directly to former president Tamas Ajan.
The 81-year-old Hungarian Ajan had been at the IWF since the mid-70s, serving first as secretary general and then as president from 2000 until his resignation in April.
The troubled federation last week appointed its third interim president in as many days, with Britain's Michael Irani, the former chair of the anti-doping commission, taking over from Thailand's Intarat Yodbangtoey.
Yodbangtoey had replaced American Ursula Papandrea in the role after an emergency meeting of the executive board.