Michael Phelps's breathalyzer test measured almost twice the legal limit

Olympic swimmer Michael Phelps's breathalyzer test registered significantly higher blood alcohol concentration than the state's legal limit, according to police documents obtained by ESPN. 

Phelps's test recorded .14 percent after he was pulled over for a speeding violation in Baltimore on Monday. Maryland's legal limit is .08 percent.

The document, a statement of probable cause by the Maryland Transportation Authority, said that Phelps' eyes were bloodshot, "his speech was mush mouth" and he appeared "disoriented, argumentative."

The officer at the scene reportedly asked Phelps to do a one-leg stand as part of a field sobriety test, in reply to which "the operator stated 'that's not happening.'"

Phelps has been charged with DUI, excessive speeding and crossing double lane lines.

He released an apology on his official Twitter account late Tuesday afternoon.