American swimmer Michael Phelps has a record 16 Olympic medals. (Cameron Spencer/Getty Images)

The headlines have not been forgiving, laden with clever puns about all things bong- and pot-related.

The British News of the World — the tabloid that first published the photo of Olympic swimming champion Michael Phelps with a marijuana pipe suctioned firmly to his mouth — ran with "What A Dope." The online newspaper The Australian titled its story, "I did the bong thing, says sorry Phelps," while the Vancouver Sun led with "Michael Phelps' golden ticket: Up in smoke?"

These stories stand in stark contrast to ones published last summer when the American Olympian was on track to his record-breaking eight golds in 2008 in Beijing to go along with six golds and two bronze in Athens in 2004. The 16 total medals are also a record.

With his dramatic wins, Phelps inspired an unparalleled frenzy. His personality and drive proved so bankable, his agent told CBS's 60 Minutes,the swimmer could expect to earn about $100 million US over the course of his career.

Phelps is now the pitchman for companies including Speedo, Visa, McDonald's and Kellogg Co.

"He was bulletproof before and he's not now," said Ken Wong, a marketing professor at Queen's University school of business in Kingston, Ont. "It's not that it necessarily paints Phelps to be a bad man but it does reduce his commercial value."

'He was bulletproof before and he's not now.'—Ken Wong, Queen's University

But what of the public's growing acceptance of marijuana?

In 1992, U.S. President Bill Clinton said he didn't inhale when he was a student. In 1998, Canadian Olympic snowboarding gold-medallist Ross Rebagliati said if there was trace evidence of marijuana in his system, it was owing to second-hand smoke.

Now, comedies such as Pineapple Express revel in the stoner persona.

For Phelps, it's different, Wong said.

"Phelps value in terms of endorsements is not predicated on him being cool. In fact, if anything, it may be predicated on him being a little dorky," Wong said. "It's predicated on him having an Olympic athlete record and having this sense of being a role model."

'For this, I am sorry'

Phelps, who in 2004 pleaded guilty to driving while impaired, has issued an apology about the new scandal.

"I engaged in behaviour which was regrettable and demonstrated bad judgment," he wrote. "I'm 23 years old and despite the successes I've had in the pool, I acted in a youthful and inappropriate way, not in a manner people have come to expect from me. For this, I am sorry. I promise my fans and the public it will not happen again."

The International Olympic Committee subsequently accepted Phelps's apology, noting they did not doubt the sincerity of his apology. And fans have shown support for Phelps too, arguing he is entitled to a certain degree of privacy.

"Shame on Michael Phelps for having a good time," wrote Pooter in CBC.ca's comments section. "Doesn't he know that he is supposed to live his life for all [of] us uptight jerks and not himself? It's certainly appropriate for Mr. Phelps to issue an apology for enjoying himself in private. Thank god an heroic British tabloid was thinking of the children."

Similarly, canadiangirl79 wrote: "Oh big deal … he is a 23-year-old kid having a good time."

The cost for Phelps — who plans on competing at the 2012 Games — may be future endorsements, Wong said.

"At the end of the day if I'm a sponsor, the only thing that really matters to me is that there's a constituency of people out there who might've respected him before who no longer do — and that means his value has been diminished."

CBC analyst Brian Dunstan speculated Phelps could run into difficulties with recently signed deals.

"He just recently signed a deal to be a spokesperson for Mazda in China, one of the biggest deals ever for a Western-based athlete. Now they're going to have some issues going forward because of the perception behind marijuana," Dunstan said.

Wong suggests Phelps would be wise to make the late-night talk show circuit and be humble about his indiscretion. But all things considered, Wong said, this scandal has to be put in perspective.

"It's marijuana. It's not like he was hitting up heroin," he said. "As a person, I don't think this makes him a bad person — it was not an act of violence, there was nobody else being hurt except himself. It was just an act of incredibly bad judgment."