Olympic champion Ryan Lochte, who became embroiled in scandal for claiming he was held up at gunpoint during the Rio Games, has been handed a 14-month doping ban after outing himself on social media.

Lochte, a six-time Olympic gold medal winner, was banned for receiving an intravenous infusion of a permitted substance without a therapeutic use exemption.

The breach came to the attention of the US Anti-Doping Agency after he posted a photo of himself receiving the treatment in a since-deleted social media post in May.

The USADA said in a statement that Lochte was not using a banned substance, but that infusions or injections in excess of 100ml within a 12-hour period are prohibited unless received in the course of hospital treatment, surgical procedures or clinical diagnostic investigations.

The 33-year-old’s period of ineligibility began on May 24, the date of the infusion, and will keep him from competing in Japan next month at the Pan Pacific Championships and at the world championships in South Korea next July.

Lochte was also expected to compete at this week’s national championships in California.

Ryan Lochte’s post that captured the attention of USADA. Source: Instagram

A 12-time Olympic medallist, Locht made headlines in 2016 over a tale about being robbed and held at gunpoint after a party during the Rio Games, which he later admitted was “overexaggerated”.

The swimmer, who won gold in the 4×200 metres freestyle relay in Brazil, missed last year’s world championships while serving a 10-month ban handed down by the United States Olympic Committee for his part in the Rio scandal.

He also had to to forfeit $US100,000 ($135,000) in prize money after winning gold in Rio.

Gunnar Bentz, Jack Conger, James Feigen, Lochte’s swimming team mates who were involved in the incident, also received sanctions for violating the USOC’s code of conduct.

Lochte, speaking at a news conference shortly after the USADA announcement, was quoted as saying he would not let his latest setback keep him from working toward his goal of earning a spot at the 2020 Olympics in Tokyo.

Lochte is a six-time Olympic gold medalist.. Photo: Getty

“I wasn’t taking anything illegal,” Lochte said.

“Everything was legal. You can get it at CVS, Walgreens, but there are rules, and you have to obey them … Don’t worry. I’m not giving up. I’m going to keep going.

“It’s devastating to my family about this because I definitely made myself a better person after Rio, and I was back in training.

“I was feeling good. I was swimming fast. My son being born. Everything was happening. Everything was perfect, and then this happened. And it’s devastating.”

-with AAP