The ITA announced last month that Ujah had tested positive for two prohibited substances.

The sprinter's A sample was found to have been positive for investigational selective androgen receptor modulators ostarine and S-23, which are regularly used as a male hormone contraceptive and as treatment for muscle wasting and osteoporosis respectively.

Ujah requested a B-sample analysis be carried out, which the ITA says has confirmed the initial test results.

The case will now be referred to the Court of Arbitration for Sport Anti-Doping Division.

"The ITA confirms that as per the athlete’s request, the B-sample analysis was carried out by the WADA-accredited laboratory of Tokyo on 19 August 2021 and the procedure confirmed the result of the A-sample," an ITA statement read.

"The ITA has thus referred the case to the Court of Arbitration for Sport Anti-Doping Division (“CAS ADD”) on 8 September 2021. 

"The CAS ADD will consider the matter of the finding of an Anti-Doping Rule Violation and the disqualification of the men’s 4x100 relay results of the Great Britain team. 

"In this regard, pursuant to the IOC ADR and the World Athletics Anti-Doping Rules: 'where the athlete who has committed an Anti-Doping Rule Violation competed as a member of a relay team, the relay team shall be automatically disqualified from the event in question, with all resulting consequences for the relay team, including the forfeiture of all titles, awards, medals, points and prize and appearance money'.

"Once the matter is settled under the IOC ADR, the case will be referred to the Athletics Integrity Unit to follow up on sanctions beyond the Olympic Games Tokyo 2020.

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

Ujah had issued a statement following the positive A-sample.

The sprinter said he was “completely shocked and devastated”, adding that he was “not a cheat and I have never and would never knowingly take a banned substance.”

Ujah competed in the event with team-mates Zharnel Hughes, Richard Kilty and Nethaneel Mitchell-Blake, who could each lose their silver medals.

Mitchell-Blake was pipped on the line by Filippo Tortu as Italy triumphed in the event.

If Britain are disqualified, the Canadian quartet Aaron Brown, Jerome Blake, Brendon Rodney and Andre De Grasse would move into the silver medal position.

China's Tang Xingqiang, Xie Zhenye, Su Bingtian and Wu Zhiqiang would be elevated into bronze medal position.

Ujah is one of six athletes identified to have been in breach of anti-doping rules at Tokyo 2020.

Bahrain's 1500m runner Sadik Mikhou, Georgian shot putter Benik Abramyan and Kenyan sprinter Mark Otieno Odhiambo were also identified in athletics.

Proceedings are underway against the trio, who were also named last month.