Lu's sample was taken out-of-competition on October 30, according to the International Testing Agency (ITA), which carries out all anti-doping procedures for the International Weightlifting Federation (IWF).

At Tokyo last year, Lu became the oldest Olympic weightlifting champion of all time when he won the men's 81 kilograms at the age of 37.

Seven of China's team of eight won gold medals in Tokyo, the best performance in Olympic weightlifting history.

Lu has not competed since then and was planning to return to action in an attempt to qualify for Paris 2024.

He is the first international weightlifter from China, by far the strongest nation in the sport, to have tested positive since 2015 and the first male to be suspended since 2010, according to the IWF website.

Lu won at 77kg at London 2012 and was promoted from second to first at Rio 2016 on the disqualification of Nijat Rahimov of Kazakhstan, in March this year for sample swapping in the weeks before the Games.

EPO has been widely used by Tour de France cyclists and endurance athletes in the past, but it does not feature at all on the list of sanctioned athletes published by the IWF.

It was found, however, in a stored sample from the Beijing 2008 Olympic Games provided by the Russian 75kg triple world champion Nadezda Evstyukhina.

She forfeited her bronze medal from Beijing when her stored sample came up positive, in 2016, for both EPO and turinabol.

Evstyukhina won at the same weight at the IWF World Championships in 2011, 2013 and 2014.

A statement from the ITA today said: "EPO is prohibited under the 2022 WADA (World Anti-Doping Agency) Prohibited List as peptide hormone (S2).

"EPO stimulates erythropoiesis (red blood cell production) and can modify the body's capacity to transport oxygen and, therefore, increase stamina and performance.

"EPO is prohibited at all times, in and out of competition.

"It is used for medical purposes in the treatment of anaemia in chronic kidney disease, anaemia in myelodysplasia, and in anaemia from cancer chemotherapy.

"EPO is a non-specified substance; a provisional suspension is mandatory following an adverse analytical finding for such a substance under the IWF Anti-Doping Rules.

"The athlete has been informed of the case and has been provisionally suspended until the resolution of the matter.

"He has the right to request the analysis of the B-sample.

"Pursuant to the IWF's delegation of its anti-doping program to the ITA, the prosecution of the case is being handled entirely by the ITA.

"Given that the case is underway, there will be no further comments during the ongoing proceedings."

Lu is the third weightlifting medallist from Tokyo to have been provisionally suspended for doping this year - all of them after out-of-competition tests.

Six athletes came up positive in tests conducted by Kazakhstan's anti-doping agency in February and March, including the Tokyo 61kg bronze medallist Igor Son.

Zacarias Bonnat, from the Dominican Republic, was positive for SARMS RAD140, a prohibited substance that is popular with bodybuilders, in tests carried out in November.

Bonnat, who withdrew his candidacy for the IWF Athletes Commission after the provisional suspension, was a silver medallist at 81kg in Tokyo - behind Lu.

Lu took a long break from weightlifting after winning in Tokyo and did not travel to Colombia earlier this month for the IWF World Championships, at which China's men's team had mixed results.

The International Olympic Committee (IOC) cut weightlifting's athlete quota by more than half between 2016 and 2024 and has removed the sport from the schedule for Los Angeles 2028, saying it will be readmitted only if there is "a change of culture" in the sport.

In the days before the World Championships, the IWF President Mohamed Jalood said weightlifting was moving in the right direction and claimed: "We are serious about catching dopers."

Jalood did not comment on specific cases but said: "The cheats will not get away with it.

"We spent $3million on anti-doping in the past year.

"The IWF is determined to provide a clean playing field for our clean athletes.

"We have put our full confidence in and trust the work of the ITA.

"We are committed to working with them to further increase testing out-of-competition, using intelligence, and we are considering all ITA recommendations to continue our progress.

"We want a clean sport and the ITA will help us in that."

insidethegames has contacted the Chinese Weightlifting Association for comment.