American swimmer Ryan Lochte banned for 14 months over doping violation

The 33-year-old was not using a banned substance, but athletes are not usually permitted to use infusions or injections in excess of 100 mL within a 12-hour period unless hospitalised or have a Therapeutic Use Exemption (TUE).

His period of ineligibility began on May 24, the date of the infusion. He will miss next month's Pan Pacific Championships in Japan and the world championships in South Korea next July.

"I wasn't taking anything illegal," said Lochte. "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."

Lochte only recently returned from a 10-month suspension after he fabricated a tale about being robbed and held at gunpoint at the Rio Olympics – although the swimmer claimed he simply "over-exaggerated" what happened.

However, he still intends to return at Tokyo 2020 in a bid to add to his haul of six Olympic titles.

"I have goals that I want to accomplish in 2020," Lochte added. "If anything this is going to add more fuel to my fire."