Michael Phelps has been suspended by USA Swimming for six months, following his second DUI arrest last week.
The American athlete, who is the most decorated Olympian of all time, will not be allowed to participate in USA Swimming-sanctioned meets until 6 April 2015.
According to the sport's national governing body, Michael, 29, violated its code of conduct when he was detained for driving under the influence.
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Michael Phelps is the most decorated Olympian with 22 medals
"Michael's conduct was serious and required significant consequences," said Chuck Wielgus, USA Swimming executive director. "We endorse and are here to fully support his personal development actions."
The athlete, who has 18 gold medals to his name, is also not allowed to take part in the world championships in Russia next August. He had previously qualified on the US team for the event that is considered the most important warm-up ahead of the 2016 Rio de Janeiro Olympics.
Two days ago Michael announced on Twitter that he was seeking professional help following his second arrest.
I’m going to take some time away to attend a program that will provide the help I need to better understand myself.— Michael Phelps (@MichaelPhelps) October 5, 2014
"The past few days have been extremely difficult," Michael wrote. "I recognise this is not my first lapse in judgement, and I am extremely disappointed with myself.
"I'm going to take some time away to attend a program that will provide the help I need to better understand myself.
"Swimming is a major part of my life, but right now I need to focus my attention on me as an individual, and do the necessary work to learn from this experience and make better decisions in the future."
Michael Phelps was arrested for DUI for the second time last week
Michael was pulled over by police for going 84mph in a 45mph zone in the early hours of 30 September. After failing a field sobriety test, he was taken to a Baltimore police station and charged with driving under the influence and speeding.
The disgraced sportsman was previously given the same charge in Maryland in 2004, when he was 19.
He had announced his retirement after winning his 22nd Olympic medal at the London Games in 2012, but returned to the sport earlier this year with the hope of competing in the 2016 Games.