The ruler of Dubai is being investigated by equestrian authorities after a horse he owns and rides failed doping tests after two races.

Sheik Mohammed said he was unaware of the doping but accepts full responsibility. The drug use came to light after testing by his staff after endurance races this year in Bahrain and Dubai.

The International Equestrian Federation said yesterday it is investigating. The federation's president is Princess Haya of Jordan, who is married toMohammed.

She has led a campaign for a drug-free sport and will step aside from her official duties when the governing body considers the case.

Her husband is one of the world's leading breeders and owners of thoroughbred race horses.

Hall of Famer John Elway's son is leaving the Arizona State program but not the school. Elway, a redshirt freshman quarterback, didn't play in a scrimmage last weekend.

Top-seeded and 10th-ranked Nadia Petrova breezed to a 6-2, 6-4 first-round win against Olga Govortsova at The MPS Group Championships at Ponte Vedra, Fla.

• Juan Carlos Ferrero of Spain advanced to the second round of the Grand Prix Hassan II, beating Christophe Rochus of Belgium, 6-2, 6-3.

• Bjorn Phau of Germany, ranked 77th in the world, upset second-seeded Mardy Fish, 6-3, 5-7, 6-3 in a first-round match at the U.S. Men's Clay Court Championships at Houston.

• Eighth-ranked Victoria Azarenka withdrew from the Family Circle Cup in Charleston, S.C., because of a right shoulder injury. Azarenka upset top-ranked Serena Williams to win the Sonny Ericsson Open Saturday. Qualifying for the Family Circle tournament begins Saturday.

Michael Vick will head back to a Kansas prison after a judge rejected an effort to keep the suspended NFL star in Virginia to work on a new bankruptcy plan.

• Free-agent defensive tackle Tank Johnson has agreed to a contract with Cincinnati. Johnson had 33 tackles and three sacks in two seasons with Dallas, but was suspended the first eight games of the 2008 season after a series of legal troubles when he was with the Chicago Bears.

A Brazilian billionaire has donated $2.5 million to Rio de Janeiro's bid for the 2016 Olympics. Eike Batista owns mining, energy, steel and oil companies whose worth is estimated at nearly $20 billion. Rio is vying with Chicago, Tokyo and Madrid for the 2016 Summer Games, and the winner will be decided by the International Olympic Committee Oct. 2.

Sacramento police have arrested two men on charges related to the theft of a bicycle belonging to seven-time Tour de France champion Lance Armstrong. Officers said that they arrested Lee Crider, 39, on suspicion of stealing Armstrong's Trek Livestrong 1274 and two other bikes from members of Team Astana. Another man, Dung Le, 34, was arrested on suspicion of possessing stolen property.

Waterloo (Iowa) Black Hawks defenseman Patrick Wey (from Mt. Lebanon) has committed to play Division I hockey for Boston College, beginning in the fall. The 6-2, 200-pound Wey, 18, scored seven goals and assisted on 27 this past season and was the United States Hockey League's seventh-leading scorer among defensemen while tying for third among the Black Hawks in plus-minus at +22.