On May 24, 2018, Lochte, a six-time Olympic gold medallist, posted an image on social media depicting himself receiving an intravenous infusion. 

A subsequent investigation by USADA, with which Lochte is said to have fully cooperated, revealed that he received an intravenous infusion of permitted substances at an infusion clinic in a volume greater than 100 millilitres in a 12-hour period without a Therapeutic Use Exemption (TUE).

Intravenous infusions or injections in a volume greater than 100ml within a 12-hour period are prohibited at all times - except for those legitimately received in the course of hospital treatment, surgical procedures, or clinical diagnostic investigations under the USADA Protocol for Olympic and Paralympic Movement Testing, the United States Olympic Committee National Anti-Doping Policies, and the International Swimming Federation Anti-Doping Rules.

All of these have adopted the World Anti-Doping Code and the World Anti-Doping Agency (WADA) Prohibited List.

"Intravenous infusions or injections in excess of 100ml within a 12-hour period received in any other setting require an approved TUE," a USADA statement reads.

"If a prohibited substance is administered intravenously or via injection, a TUE is necessary for this substance regardless of volume. 

"Administration of IV infusions over the WADA volume limit, including dietary supplement and vitamin cocktails, provided to athletes for recuperation, recovery or lifestyle reasons is prohibited at all times without prior TUE approval. 

"In situations of medical emergency, a retroactive TUE application pursuant to the International Standard for Therapeutic Use Exemptions is acceptable."

Lochte's 14-month period of ineligibility began on May 24, 2018, the date he received the prohibited intravenous infusion.

He had been entered into four events at the upcoming USA Swimming National Championships in California, where action is due to begin on Wednesday (July 25). 

Today's announcement comes less than a month after it was confirmed that Brazilian prosecutors were free to re-open criminal charges against Lochte for falsely reporting a crime, after a decision to dismiss the case last year was overturned.

The American had claimed that he and team-mates Jimmy Feigen, Gunnar Bentz and Jack Conger had been held up and robbed by men posing as police while celebrating in Rio de Janeiro during the 2016 Olympic Games.

Brazilian police claimed that Lochte had fabricated the story and that the four swimmers had actually vandalised a petrol station and were asked to pay for damages by security guards.

The case was thought to be over after Lochte, who subsequently served a 10-month suspension from USA Swimming in connection with the incident, obtained a habeas corpus in court after claiming he did not falsely communicate a crime as he did not report the alleged assault directly to the police.

But Brazil's Superior Court have granted prosecutors permission to continue pressing charges against Lochte after they decided the case was still worth pursuing despite the vast number of unsolved violent crimes in the country.

According to O'Globo, Lochte could be fined or face six months imprisonment if convicted.

In reality, though, there appears no chance of Lochte returning to Brazil and risking punishment.

The 33-year-old's lawyer Jeff Ostrow told website TMZ that the case is "absurd and disgusting".

Tiago Lins e Silva, Lochte's Brazil-based lawyer, said he would appeal.

Lochte was effectively barred from last year's World Aquatics Championships in Budapest as he was still suspended when the US Trials took place.

He has previously said he is targeting the Tokyo 2020 Olympics, warning other swimmers to "watch out".