For seven years, Lee Chong Wei, one of badminton's finest athletes, took cordyceps tablets from unmarked containers on the advice of a mysterious friend without any knowledge of how they were capsulated or stored.
It was a risky practice, unheard of in most Olympic sports, that led to a positive test last year for the man who had spent almost 300 weeks as the world number one.
"From an athlete in such a prominent position the demands of caution to avoid negligence are expected to be very high. Even though he has been cautious, Lee Chong Wei has not met the required level, a 12-page Badminton World Federation report (BWF) said.
"Mr Lee exposed himself for a completely unnecessary risk of consuming illegal substance for many years."
The 32-year-old twice Olympic silver medallist's is free to return to the court on Friday after the backdated BWF eight month ban for having the non-performance enhancer dexamethasone in his system.
His game, built on expert retrieving and incredible reflexes may need little modification before next year's Rio Games but his off-court practices require wholesale changes.
The banned anti-inflammatory was thought to been on the casing of "one or more" of Lee's cordyceps tablets, which he took two of each day from his teenage years after his mother thought it would be beneficial for his health.
Cordyseps, a natural food product, "is a fungus which grows parasitically on the larvae and pupae of insects in winter, leading to the formation of a fungal fruiting body in summers," the panel determined.
When Lee moved to Kuala Lumpur from his hometown of Perak in 2000, his mother would have the cordyseps crushed and put into gelatin capsules and sent to the promising shuttler, the BWF' panel said in their 12-page decision.
That changed, though, around 2007 when the wife "of a very influential man in Malaysia" that Lee had befriended began sending the then reigning Commonwealth Games gold medallist cordyseps as a gift.
The wife would purchase the cordyseps and have them grounded down and capsulated at a shop in the Malaysian capital with Lee taking two every morning. Lee said he didn't want to name the wife, fearing the consequences for her if she was associated with the case.
The shop owner who treated the cordyseps acknowledged the risk of contamination but opted against giving a statement and also remained anonymous for fear "it would adversely affect his business".
When Badminton Association of Malaysian (BAM) officials found Lee was taking the tablets shortly after the wife begun sending them, they advised the shuttler they, with no other additives, were safe to use as they were food-based.
BAM decided they didn't warrant testing as they hadn't led to any problems before.
"It is worrying if he has received unsatisfactory anti-doping education from BAM or other sources and/or the focus on anti-doping security has been unsatisfactory," the BWF report said.