Six days after Michael Phelps was pictured appearing to smoke marijuana, the image of another clean-cut American sporting icon has been badly damaged by a drugs scandal. Alex “A-Rod” Rodriguez, the biggest star in baseball, has a new nickname: “A-Fraud”.

A report on the website of Sports Illustrated magazine claimed on Saturday that the New York Yankees slugger tested positive for steroids in 2003. Baseball is reeling from a series of ugly revelations about the alleged drugs usage of many of its most famous players and a long-running government investigation is ongoing. This latest news is another deep wound to the reputation of a sport that is paying the price for years of inaction and leniency. Improbable feats from ageing players in the past two decades attracted admiration not suspicion, but now baseball’s age of innocence is well and truly over.

So soon after the greatest swimmer in the world was banned for three months for his transgression, the Rodriguez revelations will leave Americans wondering who among their sporting role models it is safe to trust. Rodriguez is unlikely to face action from baseball’s authorities but his standing may never recover from the allegation that he tested positive for two anabolic steroids.

The youngest person to hit 500 home runs, and the highest-paid player in Major League Baseball, he was supposed to be the symbol of a sport leaving its tainted past behind, an example of what was possible when talent combined with a strong work ethic. He was supposed to be the saviour who, a few years from now, would break the all-time home run record held by the tarnished Barry Bonds, restore credibility to baseball and strike a blow for athletes who play with honour. Rodriguez has 553 career home runs; Bonds, 762.

The report cites sources who claim that Rodriguez was among 104 players on a list who tested positive for performance-enhancing substances in 2003. Those tests were undertaken as a survey for the baseball authorities who were considering whether to introduce mandatory testing the following year. So a positive result bore no penalty and the results were supposed to have been kept confidential and the samples supposed to be destroyed.

That season, Rodriguez played for the Texas Rangers and led the American League in home runs and was voted the league’s Most Valuable Player (MVP). The following year he was traded to the Yankees, where he has won two more MVP titles and plays third base. Rodriguez and the Yankees declined to comment.

“You’ll have to talk to the union,” the 33-year-old said. He has previously denied taking performance-enhancing drugs.

Bonds, also the single-season home run record-holder, will go on trial next month. He is accused of perjury, which he denies. The Government contends that he lied in 2003 when he told a federal grand jury investigating the Balco case that he had not knowingly taken performance-enhancing substances. Last week it was reported that a urine sample provided by Bonds in 2003 had tested positive for drugs.

Roger Clemens, one of the greatest pitchers, may also face perjury charges after he denied using performance-enhancing substances at last year’s Congressional hearing on the Mitchell Report — a senator’s examination of steroids in baseball — despite apparent evidence to the contrary.

Commentators in the US yesterday said that the best course of damage-limitation for Rodriguez, if the allegations prove true, would be to come clean. That would make a change for a sport that just seems to get dirtier and dirtier.

Earnings will take a hit

Like Michael Phelps, drugs revelations will make Alex Rodriguez less attractive to sponsors, but his pockets are deep.

He is in the second year of a contract with the New York Yankees that pays him $275 million (about £186 million) over ten years. This year he will earn $32 million.

His earnings from endorsements last year were about $6 million, despite negative headlines when he divorced his wife, Cynthia, amid allegations — denied — that he was having an affair with Madonna.