American swimmer Michael Phelps, the most decorated Olympian of all time, was suspended for six months by USA Swimming on Monday following his recent arrest on a drunken driving charge.

Phelps, who recently returned to top-level competition after a two-year retirement, will also not be allowed to represent the United States at the 2015 FINA World Swimming Championships in Russia next August, USA Swimming said in a statement.

The arrest Sept. 30 marked the second time the 29-year-old Baltimore-area native had been arrested for drunken driving, the first being in 2004. In the first case, he pleaded guilty to a lesser charge of driving while impaired in exchange for 18 months' probation.