Michael Phelps has been suspended from competition for three months by USA Swimming, the latest fallout from a photo that showed the Olympic great with a marijuana pipe.

USA Swimming also cut off its financial support to Phelps for the same three-month period, effective from Thursday.

"This is not a situation where any anti-doping rule was violated, but we decided to send a strong message to Michael because he disappointed so many people, particularly the hundreds of thousands of USA Swimming member kids who look up to him as a role model and a hero," the federation said in a statement.

"Michael has voluntarily accepted this reprimand and has committed to earn back our trust."

Phelps won eight gold medals in Beijing.