Juan Manuel Marquez scored a sensational win over Mike Alvarado in their 12-round welterweight clash last Saturday, but controversy just won't spare the 40-year old Mexican boxing legend.

Marquez, who moved another step closer to become the first Mexican with world championship belts in five different division, is under scrutiny for what several boxing pundits believed a manifestation of using anabolic steroids on his chest.

Right after booking a sensational 117-109, 117-109, 119-108 win over the former Jr. welterweight champ, Marquez received criticisms from several boxing aficionados after his chest was seen filled with pimples and acne.

Acne is just one symptoms experienced by one who is taking steroids and other performance enhancing drugs. By admitting steroid to the body, it drastically leads to hormonal changes, increasing body mass and causing acne to appear.

Anti-doping and nutritionist Victor Conte also expressed his displeasure of watching Marquez vs. Alvardo fight, stating the boxing match was not played fair and square because of what he claimed as Marquez's use of steroids.

"How long will boxing continue 2 promote a 40 yr old boxer using PEDs 2 train & perform like a 20 yr old? Why not mandate random testing? $$. @onearsenewenger The PED testing done by state commissions is a joke. Marquez vs Alvarado w/ NO TESTING is a strong statement about boxing," Victor Conte tweeted via Fight Saga.

Conte, who served eight years in penitentiary containment, added that Marquez's association with G notorious with Angel Heredia, a man found out of using performance-enhancing drugs to his trainer, only validated his suspicion of cheating in boxing.

"JMM is 40 yrs old w/ muscles popping out, acne all over his chest, @Guruscience Memo as his trainer & @BobArum & boxing do get it," added Conte.

However, other boxing writers, including John Kelvin of Boxing News 24, believed Marquez's masterful win over Alvarado is not a product of using anabolic steroids but simply it is the result of the Mexican's great conditioning and savvy in the ring.

"This accusation has been floating around since Marquez linked up with strength and conditioning coach Angel Heredia, before his knockout victory over his great rival Manny Pacquiao. Juan Manuel Marquez has never failed a drug test in his career, so there is no evidence to suggest that he is doing anything illegal," Kelvin stated in his article.

"It is disrespectful of some fans to throw such damaging accusations at a great fighter who has given so many great nights and fights to the world. Marquez has got to the level he is at in his career due to hard work, determination and discipline"