WADA said it has developed a new way of detecting the banned practice following an investigation into the sport.

The 18 cases will be presented to the International Testing Agency, which is in charge of the International Weightlifting Federation's (IWF) anti-doping programme, for results management.

An investigation into weightlifting was launched by WADA's intelligence and investigations (I&I) department in August 2017.

One of its four pillars – Operation Arrow – is a covert operation which focused specifically on the practice of urine substitution at the point of collection.

"WADA I&I found evidence of 'doppelgangers' being used to impersonate athletes during the sample collection process, ensuring clean urine was fraudulently provided," WADA said today.

The new approach to detect urine substitution has been developed with assistance from confidential sources and analysis experts, WADA said.

Today's findings are another blow to weightlifting and the IWF, which is trapped in a period of crisis which could cost the sport its place at the Paris 2024 Olympic Games.

The International Olympic Committee (IOC) has voiced major concerns about the sport's governance and last week the IWF had three Presidents in three days amid the turmoil.

WADA President Witold Bańka said the I&I department should have greater powers in light of the evidence it had found.

"WADA is appalled by what its intelligence and investigations department has uncovered in this investigation," he said.

"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. 

"Once again this has shown the importance of whistleblower information and the positive difference that can be made when people with information have the courage to come forward. 

"Intelligence from well-placed confidential sources, coupled with the diligent work of WADA intelligence and investigations, is delivering significant results across a host of investigations.

"WADA will continue to do all it can to help provide clean weightlifters with a safe and healthy environment for their sport. 

"To do that more effectively in general, I believe this report shows clearly that it is time to start a discussion as to whether WADA should be granted additional powers of investigation, including unfettered access to all relevant internal documents and servers within the organisation under investigation."

German broadcaster ARD covered the subject of urine substitution in its documentary The Lord of the Lifters in January.

The film made numerous corruption allegations about the sport and former IWF President Tamás Aján, and led to the McLaren Independent Weightlifting Investigation.

This in turn uncovered widespread malpractice and doping cover-ups and led to the resignation of Aján.

Interim IWF President Ursula Papandrea was ousted last week and replaced by Thailand's Intarat Yodbangtoey, who has himself now been succeeded by Britain's Mike Irani.

"In all we do, WADA intelligence and investigations seeks justice for athletes and for clean sport," said WADA's director of I&I Gunter Younger. 

"The investigation into weightlifting has been complex, difficult and time-consuming with many obstacles placed in our way. 

"The fear and silence that pervades this sport has been a significant impediment. 

"Therefore, it has been very encouraging to receive such a large volume of intelligence as we did via WADA's confidential whistleblower platform, Speak Up.

"The success of this investigation is down in large part to the bravery of those whistleblowers.

"We also commit to identifying other new investigative methods for our partners in the fight against doping. 

"We want to detect doping wherever and however it occurs. 

"The methodology applied as part of Operation Arrow in identifying cases of urine substitution can easily be applied to sports other than weightlifting. 

"We will share the learnings and methodologies with anti-doping organisations, laboratories and athlete passport management units to ensure a global and united effort to address urine substitution."

As well as Operation Arrow, the WADA investigation into weightlifting also includes Operation Outreach, which is probing claims that a high-ranking member of the IWF was paid to promote Russian interests and to protect Russian athletes from detection.

Operation Heir is investigating allegations of an organised doping and protection scheme operating within Romanian weightlifting and Operation Extra deals with the process of collection, collation and assessment of all weightlifting intelligence received by WADA I&I.

The report from the I&I can be read here.